As a normal human kid, none, apart from him being modestly more agile and persuasive than the typical teenager. His magical jacket, his patron’s first gift, is faintly alive, however, granting him substantial (superhuman) bonuses to Dodge and Parry (as the buckles move to intercept blows or drag him out of harm’s way). His patron’s primary gift, the Chains of Perdition, are semi-animate, striking with unerring accuracy, dealing significant physical damage, locking down foes (and granting Twilight the power to drag and throw people easily 5x his own size), and eventually filling them with feelings of crippling guilt that incapacitates them if they don’t break free.
When he transforms over into the Umbral Warden form, he gains limited flight from his Sephiroth-inspired angel wing, an enormous bonus to Intimidation, generates a sphere of harrowing darkness that cloaks him and his allies and hampers foes, and enables him to “cast” Harrowing, an effect that forces foes to relieve their worst memories and deepest fears, incapacitating anyone with a weak will in a large area around him.
Finally, in the form of the Quicksilver Chevalier, he gains a magical unicorn steed who can run over water or along walls, deal excessive Charge damage with her horn, and makes flowers grow. His armor in that form reduces his Dodge/Parry noticeably, but grants him superhuman toughness and immunity to most weaker attacks. Finally, he is able to create a burst of brilliant rainbow light, blinding and stunning those too slow to react.
All of that comes at the significant cost of his mortal soul, and he’s recently learned that every action he undertakes with his powers spreads the name and influence of his patron in not just the fae world, but the mortal one as well. It would appear the Twilight Darkness seeks to expand its domain into the realm of humanity in the near future. . .