Special Summon 1 "Mermail" monster from your Deck. Its effects are negated. You cannot activate any Spell Cards. When this card leaves the field, destroy that monster. Destroy this card during your opponent's next End Phase after activation.
lol, I doubt most will even run this card. The fact that it is slow (with Night Beam seriously disrupting it if you can't chain anything else) and the fact that you're relying on the combination of this with Legacy to make a legitimate play? lol
If anything, some of the other Mermail support like Abysslinde or Diva if someone wants to run an extra deck version will make them tier 1, not this trap