We would normally suggest avoiding Dragon-type Pokemon in this scenario as they’ll be weak to Mega Salamence’s Dragon-type attacks, but we couldn’t keep the mighty Mega Rayquaza out of our list.
However, Rayquaza can also be utilized as a great ... As a dual Dark/Flying-type Pokemon, the best moveset to use is one that benefits from STAB. Sucker Punch is cheap and helps boost the energy ...
Kartana is also a strong choice as a Grass and Steel-type, but you'd need to be wary of Rhyperior using Superpower in its potential moveset since Kartana is weak to Fighting-type moves.