Pit will summon his Lightning Chariot by shouting "Lightning Chariot!" and jump into it. After this, he says "Phos! Lux! Let's go!", then a reticle will appear, and then Pit will aim at the opponents and fire at them by hitting the attack or special button. If an opponent is hit by the Lightning Chariot, they will take a massive amount of damage and fly far away. This acts like a Dragoon with less ridiculous knockback.
The Lightning Chariot is a small but extremely fast vehicle that debuted in Kid Icarus Uprising. It is operated by the two unicorns: Phos and Lux. It was originally owned by the Chariot Master, and after Pit defeats him, the Chariot Master deemed him worthy of the Lightning Chariot, entrusting it to him before passing away peacefully.