Fragments are used in Anime Warriors 3 to tier up and ascend Mythic and Secret Warriors, and each Warrior can only use Fragments earned from its own specific world.

Relics in Anime Warriors 3 come from clearing the Gauntlet, an endgame mode, with some Relics locked behind specific floors rather than available from the start.

No, Traits and Fragments aren't the same thing, Traits are passive stat boosts rerolled with Star Remnants at the Bolmy NPC, while Fragments are used specifically to tier up and ascend Mythic and Secret Warriors.

Yes, you keep the Warriors, Traits, and gear included with my purchase, exactly as shown in the listing.