If a player casts a spell that targets multiple permanents their opponent controls with ward, each of those ward abilities will trigger. If that player doesn't pay for all of them, the spell will be countered.
Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)
Ward
Whenever this creature or another artifact you control enters, put a +1/+1 counter on this creature. It can't be blocked this turn.
.)