Hollowsage

Hand disruption attached to a permanent has always punished harder than a one-shot spell, because it stacks turn over turn and forces an opponent to dump cards onto the board before they get bled dry. The unusual part is the trigger condition: this keys off the creature becoming untapped, not off attacking, blocking, or tapping for an effect. The free natural untap in your untap step cashes the discard once per turn, but the engine wants more untap events crammed into a single turn: dedicated untap effects, or tapping the creature for an ability and then freeing it up again before passing the turn. Read it carefully, because it is easy to misfire: blink does not feed it, since exiling and returning the creature creates a new object that simply enters untapped rather than transitioning from a tapped state to an untapped one. The wording rewards a deckbuilder who treats the body as a valve to be cycled rather than a beater to be swung. The 2/2 frame is the cost the design pays for an open-ended discard engine: any removal spell ends the lock the moment it resolves, so the bleed is never safe for long. The reward is a Mind Rot that keeps firing as long as the creature survives and you keep manufacturing the untap, a far more demanding ask than the oracle text lets on.