Tallowisp

Aura decks live and die by card advantage: every enchantment you cast is a two-for-one waiting to happen if the host dies, and the deck loses if it ever runs out of threats to suit up. This is the engine that solved that problem. Cast a Spirit body, dig for the Aura that turns it into a clock; cast the Arcane trick that protects it, dig for the next Aura while you're at it. Because the trigger keys off your spell types rather than the Auras themselves, every relevant card in the deck refills your hand instead of just one designated tutor. The body matters too: a 1/3 survives the small removal and the chip damage that would otherwise blow out a one-creature enchantment plan, so the thing wearing your Auras tends to be something else, while this stays back and keeps the cards coming. It is a tutor-on-a-stick narrow enough to be fair (it only finds enchant-creature Auras, only when you cast the right spell type) and broad enough to anchor an entire archetype, which is exactly the line a build-around wants to walk. Outside that shell it does nothing, but inside it, it is the reason the deck is a deck and not a pile of fragile two-card combos.