Be ready with your own backup counterspell
That's why tutors, cantrips, or card filtering spells often top most played lists of their respective colors
Im sure you can find the value of this card quite easily when you look at what wants it
During your opponent's next turn, the Defending Pokemon can't be evolved by playing a card from your opponent's hand
If the target creature is an illegal target by the time the spell tries to resolve (most likely because it has left the battlefield in response), it won't resolve and none of its effects will happen
Still, this card is not perfect: Its difficult to build a deck that can make Murktide shine entirely, apart from UR Murk: cheap spells, counterspells and removals are usually a mix only playable in Izzet decks