He joined Super Smash Bros. Brawl as a summonable Assist Trophy, and returns as such for Super Smash Bros. Ultimate. A Mii Fighter Costume modeled after him is also available in the latter's base game.
Isaac is young man with a calm demeanor and a natural born-leader with a large trust in his friends. He is willing to do anything for the greater good, even if it means seeking counsel from the enemy and defying those who set him on the path of his hero's journey. He is also deeply religious, having grown up in a community that reveres a deity-like being; it is an aspect that carries into his adult life, having resorted to constant prayer nearly every day. Isaac is capable of using Psynergy, a type of mental-based magic power; he is also what's known as a Venus Adept, a type of human that is capable of manipulating plantlife and the earth itself. As with other JRPGs, Isaac is a silent protagonist with a blank-slate personality, leaving his actions and the interpretation of his thoughts up to the will of the player.
A 14-year-old Isaac's life would be forever changed following the tragic accident of the Mt. Aleph Boulder tumbling down onto his home village of Vale in Weyard, destroying several houses and seemingly killing some of his friends' parents, as well as his own father Kyle. In a shock-induced daze, Isaac wanders off the village on his own, with his friend Garet following close by. The two eventually encounter two strangers, calling themselves Saturos and Menardi, who are revealed to be behind the accident as they were attempting to enter Mt. Aleph's Sol Sanctum. The boys are then rendered unconscious by the two Mars Adepts and blanket Vale in darkness as they leave. Driven by guilt, grief, and vengeance, the two boys wake up and decide to learn how to be Adepts, assisted by their friend Kraden.
Three years later, a now 17-year-old Isaac has developed his Psynergy powers alongside Garet and Jenna. One day, Kraden tasks them to go to the Sol Sanctum for investigative purposes, despite it not being normally permitted by the Vale elders. Coincidentally, Saturos and Menardi also return the same day the trio set about in their task; at the Sanctum, they overhear the duo talking amongst themselves about how to use Kraden in their plan of infiltration. Kraden warns Isaac and his party that they may be there to rob the Sanctum and urges them to continue with their mission. Inside, Isaac and company not only discover that Saturos and Menardi are Mars Adepts, but they also find three of the four Elemental Stars and retrieve them by the behest of Kraden as he plans on researching them. However, the Mars Adepts kidnap Jenna and Kraden and hold them hostage in exchange for the Stars; they then reveal two new companions that have joined them, being a Mercury Adept named Alex, and — to everyone's surprise — Jenna's brother Felix, who was presumed dead during the Mt. Aleph Boulder accident. Isaac and Garet move to retrieve the fourth Star, the Mars Star; once they remove it from its pedestal, Mt. Aleph starts to erupt and a powerful deity known as the Wise One appears before the boys, who tells them that Saturos' group plan to use the stars to light the four Elemental Lighthouses which will restore a dangerous power called Alchemy and unleash it onto the world. The Wise One tasks Isaac with keeping the Mars Star and teleports the boys to safety and redirects the lava away from Vale, while Saturos's group flee with Kraden and Jenna still in their captivity.
Upon arriving at Vale, the boys are sent to Vale's Sanctum to explain the situation to the residents, with the town's Great Healer also relaying a message from the Wise One, as the fate of Weyard rests on Isaac and Garet's decision to embark on on a quest to stop Saturos and his crew. Isaac ultimately decides to do it, leaving his mother Dora too distraught to properly send him off the next morning. After a hearty farewell from the townspeople, Isaac and Garet go on with their journey through the continent of Angara.
Over the course of the game, Isaac and Garet better their Psynergy skills as they battle wild creatures who have been driven mad by Psynergy Stones that were scattered by the erruption. They also meet two more Psynergy users, being the Jupiter Adept Ivan and the Mercury Adept Mia (who happens to be Alex's cousin), who join the boys in their pursuit of Saturos and Felix's group. Their travels eventually take them to another continent, Gondowan, where they stop at the city of Tolbi and meet its ruler, Lord Babi. He explains that he has been seeking Adepts to travel to a hidden city called Lemuria to retrieve a stockpile of Lemurian Draught, a special fluid that increases one's lifespan if they drink it; he specifically needs Adepts as they are the only ones who can control a Lemurian Ship as to head to the city and can clear a path for Babi's men so they can construct a special Lighthouse nearby (for ships containing Draught) in an area that just so happens to be near the the continent's Venus Lighthouse, being Lalivero. Isaac agrees to work for Lord Babi, as it is mutually beneficial.
Upon arriving at the Venus Lighthouse, the group discovers that Saturos has taken yet another hostage, being a young Laliveran girl named Sheba. The groups come to a tense standoff, with Saturos explaining that she is a Jupiter Adept, who will be needed when they inevitably head for the Jupiter Lighthouse. He then tricks Isaac into handing over Ivan's Shaman's Rod, as it is also important for the Jupiter Lighthouse, and immedialtely launch an assault on Isaac's team; however, despite Saturos, Menardi, and their company being swiftly defeated by the young Adepts, the Venus Star still finds its way into the Lighthouse's well, causing it to tremble and release Psynergy onto Saturos and Menardi, allowing them to merge into a two-headed dragon known as the Fusion Dragon. Eventually, Isaac and his party ultimately prevail against the beast, with Saturos and Menardi meeting their demise as they return to their original forms and fall into the well.
The last member of Saturos' party, Felix, decides to flee with the hostages after being visibly intimidated by Isaac's incredible victory, determined to complete his masters' quest. He and Sheba then fall off the tower as it goes through an earthquake; though initially assumed dead, accounts from the Lalivero people imply that they survived due to Sheba's supernatural tendency for coincidences being played out in her favor. Isaac also learns that the earthquake resulted in a peninsula called Idejima from being torn off the mainland, and assumes that Felix, Sheba, Jenna, and Kraden are all there to continue the quest. Isaac, Grant, Ivan, and Mia use the Lemurian Ship to sail off into the ocean, promising to fulfill Babi's request, while still in pursuit of Felix.
Golden Sun: The Lost Age
Isaac and his party are relagated to minor supporting characters in the sequel, as the focus is shifted to Felix's party. However, his whereabouts can be alluded to when Felix is chatting with townsfolk in certain parts of the game.
Picking up directly after the events of the first game, Isaac, Garet, Ivan, and Mia are still in pursuit of Felix, Jenna, Kraden, and Sheba. During their travels, its hinted that they had incredible difficulty sailing through the Eastern Sea as well as hearing the news of Lord Babi's passing, meaning he had failed in his promise to collect Lemurian Draught. Isaac and his group finally reunite with Felix's group at Jupiter Lighthouse after Felix saves him from Karst and Agatio. The two camps retreat to the city of Contigo, where Felix fully explains what has been going on; the Mt. Aleph Boulder incident had not killed anyone at all, as Saturos had saved Felix, his parents, and Kyle but had taken them prisoner in his home village of Prox as to coerce Felix into helping him to activate the Lighthouses. Felix also reveals that the entirety of Weyard has been slowly deteriorating ever since Alchemy was sealed by the ancients, with the ocean consuming the landmasses bit by bit. This revelation shocks Isaac to his core, as he still believed that unleashing Alchemy would cause destruction; when asking Felix why didn't he tell him sooner as his party could've assisted, Kraden interjects by suggesting Isaac would not have betrayed Vale's teachings so easily. Upon hearing from the oracle Hama that Karst and Agatio will be killed by a powerful force before they can activate the Mars Lighthouse, Isaac and Felix's parties agree to team up to fulfill the mission.
The group arrive at Prox, where the Mars Lighthouse is located, and Isaac is forgiven by the townsfolk for his actions when they are made aware that it was him who killed Saturos ad Menardi, ensuring that they trust him and Felix to save Weyard. The mayor of Prox, Puelle, then orders the release of Kyle and Felix and Jenna's family, only to discover that they have headed for the Lighthouse as well. As Isaac and Felix's parties arrive at the Lighthouse, they discover Karst and Agatio to have been defeated by a mysterious entity they call "the eye" and are on the verge of dying. At the top of the Lighthouse, the group is shocked to find the Wise One awaiting them, who angrily confronts Isaac on why he has defied his commands. The two have a debate, with the Wise One's reasoning for his actions being that humans will destroy Weyard themselves, believing that Adepts will use their abilities for personal gain and sinister purposes. The group is also shocked to learn that Alex has returned to the peak of Mt. Aleph and is awaiting for Alchemy to be unleashed, as it will cause an explosion called "the Golden Sun" and he will be at its center, thus acquiring the power for himself. Nevertheless, Isaac urges Felix to throw the Mars Star into the beacon.
The Wise One tries to prevent their actions by summoning "a miracle" they must defeat, being a three-headed dragon; to Isaac's horror, he discovers that the dragon is in actuality a fusion of his father and Felix and Jenna's parents who have been forced to fight their children. Despite knowing this, he stays silent for a majority of the battle, knowing he must sacrifice what is closest to his heart to save the world. The group eventually prevails, to which they ultimately discover just who exactly they have slain. Isaac comforts them in their extreme horror and grief by saying that they would've understood the situation they found themselves in and why they came to their ultimate decision. Isaac stays behind with his dying father as Felix activates the Mars Lighthouse.
With all four Lighthouses activated, they begin to react in unison and bathe the land in elemental magic energy. The Golden Sun event then follows, with Alchemy being fully restored and Alex getting killed by the blast. As the magical energy spreads, in a miraculous event, the bodies of Isaac, Felix, and their parties as well as their gravely injured parents are hit with the power, which in turn saves the parents' lives, who are then transported back to Prox and nursed back to health. On the journey back home, Isaac and Kraden contemplate the effects of Alechemy's return, believing that its use depends on the Adepts all over the world, as well as the Wise One's true motivations being to test the strength of Isaac's heroics as he fully knew that Alchemy would save the parents' lives. Upon arriving at Vale, the group discovers that it has been wiped completely off the map due to the explosion; at first they believe everyone had died, but Isaac soon sees his mother alive and well, explaining that the Wise One telepathically told them to evacuate before hand. Isaac and his parents embrace for the first time as a full family as they celebrate the survival of the entire townspeople and the entire group's return home.
Golden Sun: Dark Dawn
In the thirty years that follow, the aftereffects of Alchemy not only renewed Weyard's life force, but it also drastically reshaped the landscape with constant natural storms. Isaac and his party have also come to be known as the Warriors of Vale, though whether they are viewed as heroes or not is dependent on the person. Isaac himself has become further religious, praying daily to the Wise One for guidance mainly because he blames himself for all of the natural disasters that have occured. He and Garet take residence in Goma to observe the Psynergy Vortexes that have popped up due to the Golden Sun event. Isaac also marries Jenna, who become parents to a son named Matthew and train to become an Adept.
One day, when Matthew is sixteen, he and his friend Karin travel to the Psynergy Stone mine to rescue their friend Tyrell after crashing Isaac's soarwing. Their respective parents, Isaac and Garet, follow them ahead, taking the time to set up obstacles for them to overcome with their Psynergy as to continue their training. However, when the group arrives at the mines, they find Tyrell unconscious near a Psynergy Vortex which has since drained him of his Psynergy. Isaac and the group then defeat a Tangle Bloom and recover Tyrell, where they also find the soarwing destroyed. Isaac then informs Tyrell that he will need to go on a trip to find replacement parts to repair the ship.
The next day, Isaac tasks Matthew and Karin with joining Tyrell on his job as he cannot do it alone, using it as a training opportunity for them. Secretly, Isaac also believes that a powerful force has targeted the Wise One, and hopes that Matthew and his team can investigate it. After Matthew and his group are sent off, Isaac is not seen for the remainder of the game's story and is barely referenced by other characters. At the very end of the game, on their way back home, Matthew, Karin, and Tyrell discover that Isaac and Garet have gone missing and that an abnormally large Psynergy Vortex has appeared near the house.
Isaac appears as a summonable Assist Trophy. He will reside in the background and perform the Psynergy spell Move, which involves him conjuring a hand-shaped energy field that constantly moves in one direction all the way beyond the Blast Zone and will push any characters or Items in its way. Much like in Golden Sun the spell does no damage, but is very difficult to escape from as the hand is quite large. It can also affect invincible opponents, since it only pushes characters. Isaac will perform Move three times before disappearing.
Isaac must be unlocked in order to have a chance of him showing up in a match. To unlock Isaac, players must compete in 200 matches to completion.
A strong-willed Psynergy adept of the bloodline of an ancient race thought to have been lost with the downfall of civilization. He can manipulate earth-based forces and is also a highly skilled swordsman. He sets out to protect a lighthouse that can release the sealed powers of alchemy. In Smash Bros., he uses "Move" Psynergy, which creates an energy field that pushes foes away.
- GBA - Golden Sun
- GBA - Golden Sun: The Lost Age
Isaac returns as a summonable Assist Trophy after being absent from Super Smash Bros. for Nintendo 3DS and Wii U, though this time with a few notable changes. He no longer stays in the background and is now capable of moving around by using Teleport. While he can still use Move, more of his Psynergy attacks have been added to his moveset and is now capable of causing damage; these include Lift, where he grabs an opponent and attempts to life them past the upper Blast Zone, and Pound, where he slams an opponent from above with a giant energy fist. Players can KO him to earn a point in a Timed match. He is also one of the handful of Assist Trophies that can perform an Air Dodge.
A costume for the Mii Swordfighter modeled after Isaac is available in the base game and must be acquired separately in the Shop; the Wig is available for 450G, while the outfit is 650G.
The sword it uses is the Short Sword. It is a common Light Blade that can be equipped by Isaac, Garet, and Ivan in Golden Sun, by Felix, Piers, and Jenna in The Lost Age, and by Matthew, Tyrell, Karis, Amiti, Eoleo, and Himi in Dark Dawn. They are sold in shops at Vale, Vault, Daila, Madra, and Patcher's Place. As it is a common blade, it does not sell for much value. In Dark Dawn, it gains a special ability called Critical Strike, a non-elemental Unleash attack that multiplies the user's physical attack stats.
A Spirit of Isaac is available in the base game. It is a Primary Grab Spirit under the Ace class. His Spirit Battle uses a Mii Swordfighter wearing the Isaac costume and is assisted by Palutena (representing Mia), Robin (representing Ivan), Roy (representing Garet), and Isaac himself. All of the opponents' magic abilites (except for Isaac), which is meant to mimic their Psynergy attacks, will also be powered up. The stage is the wooden bridge section of Wuhu Island, meant to resemble the bridge that leads to Vale (with Maka Wuhu in the background a mimic for Mt. Aleph), and the song that plays is "Battle Scene / Final Boss - Golden Sun". All three opponents must be defeated to win.
The Isaac Spirit can also be summoned by using the Spirit Cores of his party members Garet, Mia, and Ivan. It is also enhanceable; when it reaches Level 99, it will transform into the older Isaac from Dark Dawn. It is a Primary Grab Spirit under the Legendary class.
|1169||Isaac (Dark Dawn)||Golden Sun: Dark Dawn||★★★★||Energy Shot/Attack Resistance ⬆||3|
- In Super Smash Bros. Ultimate, Isaac cannot be summoned on Spear Pillar, Spirit Train, and King of Fighters Stadium.
- Isaac is the only Assist Trophy to gain an updated moveset.
- Isaac is one of two Assist Trophies to skip an installment, the other being Gray Fox.
- The website for Ultimate makes a note of this, as they are the only two veteran Assist Trophies to have promotional images shown off much like the newcomers.
- Isaac's voice actor is Teiya Ichiryūsai, who also did the Japanese dialogue for Krystal on Lylat Cruise's hidden dialogue Easter egg.
- The hand that appears in Isaac's attacks in Ultimate is a re-skinned model of Master Hand.
- Isaac is the only character capable of stopping Super Sonic in Brawl, causing Sonic to Self-Destruct with good timing.