Rayquaza

As the premier offensive threat in Anything Goes, Mega Rayquaza boasts incredible attacking stats backed by a stellar movepool. Base 115 Speed is quite solid and lets it outpace many offensive threats, such as Primal Groudon, Yveltal, Xerneas, and Zygarde-C. Mega Rayquaza further benefits from being able to hold an item unlike other Mega Evolutions, making it unpredictable and dangerous. This allows it to run multiple movesets viably, making Mega Rayquaza incredibly difficult to deal with before its set is revealed. However, while base 115 speed is quite fast, Mega Rayquaza can be outpaced by Arceus as well as other faster threats such as Mega Gengar and Ultra Necrozma. While its bulk is above average for an offensive threat when combined with Delta Stream, repeated uses of Dragon Ascent leave it vulnerable to priority from the likes of Arceus and Marshadow.