Hue I didn't actually think about it throughly, just a joke.
Also I srs need someone to respond. Suicune, milotic, and vap (Sorry swampert, HPGross doe) were all some of the best counters to metagross in ADV. They could take his hits, heal it off, and hit harder with surf. So with the former 2 prob going to be a reality for a while, we will be left with vap at the start.
The split brings this:
252+ Atk Choice Band Metagross ThunderPunch vs. 248 HP / 252+ Def Vaporeon: 272-322 (58.7 - 69.5%) -- guaranteed 2HKO after Leftovers recovery
Then you could say, well maybe we drop the waters, and go skarm since it can spike, rest, and whirlwind metagross out, while absorbing all his hits.
Choice Band Metagross Rock Slide vs. Skarmory: 79-93 (23.6 - 27.8%) -- possible 5HKO after Leftovers recovery
Then with the split, physical thunderpunch gives this
252+ Atk Choice Band Metagross ThunderPunch vs. 252 HP / 252+ Def Skarmory: 158-186 (47.3 - 55.6%) -- 21.5% chance to 2HKO after Leftovers recovery
Now I'm not perfect, and I could be missing something (aside from magneton because the right EQ scout basically reks u) so please give me your input and feedback,
but as I see it metagross might be 2OP