Aragorn the King
Literally a duck
Do you need it for Hyper Offense? If so your options for countering it are limited. There's Victini, which can switch in on anything, but can't handle any set with EQ, and is outsped at +2. Mega Scizor can switch in, but if you're using the most common (3 Attacks + SD) set, you can't recover, and you can't do impressive damage to it immediately. Mega Gyarados is nice, since in its normal form it can intimidate meta, soak up a zen headbutt, and boost until it can KO meta (after mega evolving into mega dos) with crunch. Scarf Landorus-T and Manectric both outspeed, KO, and intimidate, but they can be worn down easily, and the former falls to the rare ice punch + agility combo.Is there a Pokémon of offence that can successfully counter both Metagross sets without being a Mega? I tried out Talonflame but it can get outsped and OHKO'd by Agiligross Zen Headbutt...
Btw, if you're using BO, there are many more options (that I won't list because I expect you're not).