There are few cards in Magic with the potential for as many shenanigans as this card. This card can easily both benefit you (stopping effects like Aboroth's weakening cumulative upkeep) and harm your opponents (making Jhoira of the Ghitu the saddest panda). There are just so many different ways to abuse and create rage with this card. Now, it's main problem is that it costs 5, meaning the only place it will really see play is EDH, but if it were much cheaper, it would be too silly.
Pros: Extremely abusable, can create an easy lock
Cons: Costs 5