If all of Storm the Seedcore’s targets are illegal at the time the spell tries to resolve, it won’t resolve and none of its effects will happen. Creatures you control won’t gain vigilance and trample.
14-04-2023
wotc
You choose how many targets Storm the Seedcore has and how the counters will be distributed as you cast the spell. Each target must receive at least one counter.
14-04-2023
wotc
If some of the creatures are illegal targets as Storm the Seedcore tries to resolve, the original distribution of counters still applies and the counters that would have been put on the illegal targets are lost. They won’t be put instead on a legal target.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.