Inexorable Blob
Most delirium payoffs spend the condition once and move on: a spell gets cheaper, a creature grows, an ability flips on and stays there. This one re-checks the requirement every combat and pays out every time, which is where its whole personality lives. Once four card types sit in the graveyard, each attack mints a 3/3 Ooze that arrives already tapped and attacking, so the trigger contributes to the board the turn it fires rather than the turn after. The 3/3 body is a modest attacker on its own until delirium turns on; the value is in the trigger's cadence, not the stats. The critical structural fact is that the tokens are plain 3/3s with no attack trigger of their own. Only the original Blob generates Oozes, so the engine has a single point of failure: kill it and the army stops growing, no matter how many tokens already stand. That makes it a magnet for spot removal rather than something that outruns it. What it does resist is delirium falling off later. Because the condition is checked on the declare-attackers step, not on damage, a single swing banks a permanent 3/3 the moment the attack trigger resolves; the token needs no combat damage to stick, and you keep it even if your graveyard is later exiled or shuffled away. Fill the yard with the right spread of types, then convert that bookkeeping into fresh bodies for as long as the Blob survives to swing.

