Creature â Eldrazi Drone
Devoid (This card has no color.)
: Each creature with toughness greater than its power can't block this turn. ( represents colorless mana.)
You compare the power and toughness as you declare blockers, not as Immobilizer Eldraziâ€™s ability resolves. For example, if you control a 3/3 creature as the ability resolves, then later that turn it gets +0/+1 such that itâ€™s 3/4 as blockers are declared, it wonâ€™t be able to block.
If a creature has already been legally declared as a blocker, Immobilizer Eldraziâ€™s ability wonâ€™t change or undo that block.