Steelix

Mega Steelix is more of a niche option in Battle Spot Singles, but it has the potential to be dangerous on a Trick Room team with Cresselia as a teammate, especially in a metagame filled with fast and frail attackers. It finds usefulness due to its ability to utilize Curse effectively, after which it is able to OHKO most Pokemon in the format, including Mega Kangaskhan and Garchomp.

While Mega Steelix does not have to worry about even super effective physical attacks, special attacks are unfortunately a major weakness. It cannot stand up to Water-type attacks like Hydro Pump and Scald or to Focus Blast. It also heavily relies on Trick Room to be effective and therefore only fits on one kind of team, with Cresselia as a mandatory partner. On top of that, it must use Curse before attacking, giving it only two turns of Trick Room in most situations. For these reasons, it faces heavy competition from Mega Mawile, which can still be effective when outside of Trick Room. However, Mega Steelix is still a very powerful Pokemon while under Trick Room and can even be used to counter opposing Trick Room teams that use Mawile.