Earsplitting Rats

The discard here cuts both ways, and that symmetry is what defines the card's awkward niche. The enters trigger empties a card from every hand, including yours, which makes it a poor fit for any deck trying to develop a board or curve out: you are paying four mana for a 2/1 that costs you a card and your opponents one apiece. The regeneration clause then asks you to keep feeding it cards from your own hand to keep it alive, so the body that survives combat is the same body that is bleeding your resources to do so. That combination points at exactly one home: a dedicated discard or hellbent strategy where emptying your own hand is the plan, not the cost. Wheel-and-deal builds that want everyone hellbent, madness shells that want cards in the bin rather than the hand, and grindy attrition decks that treat their own discard as fuel are the only places where both halves stop fighting each other. Outside that context the math never resolves, because the symmetrical hand-stripping helps the opponent at parity and the regeneration only matters once they have removal worth dodging. It is a creature built for a deckbuilding thesis most decks do not share.