i think this card wouldn't change so much the game
spending 5 and use a card to kill a creature isn't so much usefull
otyugh costs 5 but is a kill at turn
rain of fire costs 7 but may kill many creatures
toadfish costs 5 and poison 1 creature at turn
If you want to neutralize completely a creature it would be fine lobo and poison
stasis and poison seems to me like using a bazooka on an ant