Simon's main gimmick is his whip, which has a sweetspot in the form of a tipper and lets him damage and kill from a safe zone. As such, he plays best when at medium-long range and suffers from fighting in close combat. He also doesn't have many viable escape options for close combat, which makes him easy to pressure.
Simon's whip gives him tremendous reach for many of his moves, allowing him to attack opponents from a greater distance.
Simon's long-ranged attacks have noticeable startup lag and can leave him open to attack.
Some of Simon's attacks have unique sound effects taken from his original series. His whip uses the lashing and striking sounds from some of the old Castlevania games, while his uppercut attack uses the sound effect from Symphony of the Night.
Neutral Attack: Two strikes with the whip coiled followed by a flurry of whip strikes and an upward finisher. Simon holds the whip lengthwise with both hands.
If the button is held, Simon will perform the whip twirl from Super Castlevania IV. It is freely controllable and is able to destroy weak projectiles, such as Metal Blade and Missile. Functions similarly to Sheik's old Chain. Deals 1% damage when hit.
Forward Tilt: A swing with very long range but notable startup lag. Based on the iconic whip strike introduced in the first Castlevania. Deals 15% damage.
Up Tilt: A quick swing that covers his head.
Down Tilt: A combination of Slide and Jumping Slide (if the button is pressed again). Taken from Richter in Castlevania: Symphony of the Night. Deals 6% damage, 8% on jumping slide.
Dash Attack: Simon charges forward, spinning his whip around him. This is a move borrowed from Richter in Castlevania: Symphony of the Night. Deals 12% damage when all hits connect.
Forward Smash: A whip crack. Outranges Corrin's forward smash, making it the longest uncharged forward smash in the entire game. Deals 20% damage.
Up Smash: A vertical whip attack, boasting impressive vertical range but poor horizontal hitboxes. Deals 20% damage.
Down Smash: Simon spins his whip around his body, with great range on both sides. Deals 21% damage.
Floor Attack (Front):
Floor Attack (Back):
Floor Attack (Trip):
Neutral aerial: A whip twirl around Simon's body.
Forward aerial: Forward whip swing. This can be angled slightly upward and downward at roughly a 20 degree angle. It also acts as a tether recovery. Based on the directional whip mechanics from Super Castlevania IV.
Back aerial: Backward whip swing.
Up aerial: Upward whip swing. It has impressive vertical range but poor horizontal hitboxes. It is currently unknown if it can be angled or if it's a tether recovery. Deals 15% damage.
Down aerial: A divekick, similar to the ones performed by most protagonists upon obtaining the ability to double jump. Simon and Richter both obtained this ability in Harmony of Despair. It appears to Meteor Smash in its earlier frames. Deals 15% damage.
Grabs and Throws
Pummel: Hits the opponent with his knee.
Forward Throw: Spins the opponent around once and throws them forward.
Back Throw: Flings the opponent behind him.
Up Throw: Knocks the opponent into the air with his whip.
Down Throw: Slams the opponent on the ground. Deals 10% damage.
Up Taunt: Holds the Vampire Killer in the air, coiled up.
Down Taunt: Cracks the Vampire Killer on the ground next to him.
Side Taunt: Holds the Vampire Killer lengthwise and spins it around himself twice.
Appears on-screen surrounded by light.
Holds the coiled Vampire Killer in the air and unleashes it as he spins once.
Whips the ground around him twice before holding the Vampire Killer taut.
Jumps up to grab a Magic Crystal and then whips forward. Simon will then continuously whip and jump as the camera cuts to a side view, referencing a phenomenon when the A and B buttons are held after collecting an orb in the original Castlevania.
Simon's design is based on his appearance from the older Castlevania games, most noticeably on the X68000 release of Castlevania Chronicles with some elements from Super Castlevania IV, such as his shoulder pad and the spiked bracelet he wears on his upper arm.
His "Vampire Killer" whip's design is based on its fully upgraded form (a chain whip with a morning star on its top) in the Castlevania games, while its cross-shaped hilt pays homage to the Combat Cross weapon in the Lords of Shadow sub-series, in which that universe's version of Simon Belmont wielded said weapon.
Simon's idle animation, walk, and jump are all inspired from the original Castlevania, though his backwards jump and roll are taken from Richter's backflip and backdash animations respectively.
Simon's render is based off of the boxart of the original Castlevania, now turned to face the side and with the Vampire Killer in front of him.
It also slightly resembles Mario's render pose in Brawl, albeit mirrored horizontally.
Simon is the first character to be introduced in the same installment as his clone since Melee, where Marth was added to the roster along with his clone, Roy.
He is also the first third party character to ever have a clone.
The screenshot of Simon holding an axe in front of Bowser is a reference to Super Mario Bros., where the axe is often the key to defeating Bowser and his imposters in castle levels.
In the direct, the words: "Richter originated some of these moves. So, Simon also echoes Richter!" are seen on the bottom. Sakurai also mentions that because some of Simon's moves originate from Richter, it's "hard to say who's really echoing who".
Not counting Echo Fighters, Simon is the only newcomer to be human.
Simon's up Smash was inspired by his multi-directional whipping ability in Super Castlevania IV as well as the limited downward whipping of Castlevania Chronicles.