Wurmquake

The absence of an in the cost is the first thing to understand: the token size is pinned to the total mana that actually paid for the spell, six on the front and ten off the flashback, moved only by a cost reducer or a tax. That fixed floor matters because the real scaling lives in the corrupted clause. The card always mints one base Wurm, then a second copy of that same body for every opponent already sitting on three or more poison counters. Against a single loaded opponent that is two large tramplers; across a table where the poison has spread wide, it is a whole rank of Phyrexians arriving at once, each carrying toxic 1 to keep the counters climbing. That feedback is the design's whole intent: the poison you have stacked all game converts into the width that finishes it, and the fresh Wurms feed the very clock that paid them out. The card behaves less like a mana sink than a threshold check, sizing its output to how much of the table you have already corrupted rather than to how much you can pour into it. The flashback cost keeps the loop alive after the board has been answered, letting a poisoned table cash in a second army once the graveyard is the only resource left, and the same corrupted count applies again to double up the yield.