Vaddal, Tidefront Raider

Diving
Merfolks you control have idol (Whenever this creature enters the battlefield or deals combat damage
to a player, you may put a +1/+1 counter on target creature with lesser power.)
Whenever Vaddal, Tidefront Raider attacks
change target merfolks basepower
to Vaddal, Tidefront Raider's power until
end of turn.