Its difficult to find balance with sweepers, as they have a way of either ending the game on their own or not mattering much at all, with games where they fall somewhere in-between being rarer than either extreme
It is also possible to win a match by surrounding the enemy deck leader and making them unable to play cards
Once per turn: You can discard 1 Fairy monster, then target 1 of your banished LIGHT Fairy monsters
Like, I dunno, a machine that eats time really could've been a lot interesting, y'know
With such an awful Ability, the only way that Gyarados might compensate for it is with an excellent attack
Most decks in our Standard format have some way to accelerate Energy, like Archeops in Lugia VSTAR decks or Mirage Gate [Lost Origin] in Lost Zone Box decks, which allow Mew ex to shine in almost all viable decks