Voting for ThickFatAzumarill's Porygon2: I can't not pick the digital duck. Checks every variant of metagross, counter every variant that doesn't carry hammer arm. Really solid providing a 2hok with foul play and simply recovering on anything else. Also does well vs a lot of other physical threats like mimikyu, zard-x, excadrill and lando. Trick room is also really cool here if you want a semi tr team or just want it there to set and screw over faster offensive mons
I'm going to try and do this every week if possible starting now, but here's why I didn't pick any of the other options. Keep in mind that I'm also voting based of metagame performance, since that's just as important as combating the current victim of the week! (I promise these will eventually get better)
Feesh Squad's Mega-Scizor: Yeah, It's a hard metagross counter. Outside of that though, It's really just underwhelming in the current meta.
cant say pretty much summed up the bulk of what I was going to mention, but in addition to that there really are a whole lot of better megas out there to pick from. Even on a double mega team, sciz is just really not that great. On paper it's cool, not so much in reality
Chemcoop's Dugtrio: Cool meme dude, ngl. I love this thing in ou, but not so much bss. Takes a z move, hard to get in (pretty much needs some godly plays or 1-2 slow pivots to back it up, or sacking something else) and just kinda sucks. But nonetheless, everyone loves a good meme, so you win the meme submission if there were one :P
Lionyx's Mega-Charizard-X: I really like this as well, though my biggest problem with it would be getting a safe mega evolution. The only two moves you can safely come in on are bullet punch and earthquake. Mash surprisingly does a fair chunk and has the possible +1 attack behind it, so not the safest choice. For me, p2 does a very similar job and is a lot safer, so zard-x barely misses out unfortunately
The Squash's Aegislash: Was tempted to vote for this as well. Comes in on anything that isn't earthquake and gets an easy ohko. Also a perfect check. Only reason I didn't pick this is simply that I like to use p2 more. Nothing at all wrong with the submission, just not my cup of tea. I would have personally done a weakness policy set which is a super nice lure and still destroys majority of the meta lol
Vif-Argent's Volcarona: MAN I WAS SO EXCITED WHEN YOU RESERVED THIS, but you lowkey blew it :x There was so much potential for a bulky flame body set which takes complete advantage of metagross and easily sets up (let's be real, setting up on metagross is no easy feat). Unfortunately you went with the standard offensive, which is why I didn't vote for this. I would have voted for a bulky set in a heartbeat. Bulky is just so much better for metagross, man I wish you posted that instead lmao
BlizzardHero's Bronzong: Okay yeah, another hard metagros counter. Convert my scizor statement over to bronzong (minus the mega stuff) and you have my reasoning. Cool mon, does the job, but not that great in the current meta unfortunately
Solerme's Gastrodon: I like it. Nice anti-meta mon, can be placed into some really good matchups, and also some really horrible ones at that. Does the job perfectly with metagross, though it's a little too inconsistent for my liking
Kanono90's Mega-Steelix: I mean... well yeah, it destroys it. I would have put rocks on this set, given how easily you force out metagross and set up rocks. Unfortunately, viability is what holds this mon back for me
3heartschall's Mega-Gengar: Well, we've got no viability problems here of course. What I really don't get is that defensive investment. I get that it lives a burnt metagross zen headbutt followed by bullet punch, but in the meantime you're putting yourself at 193 speed, which makes you no longer tie with koko and other mega-gengar, while making you slower than +1 adamant blaziken, +1 adamant gyarados-mega, and also scarf chandelure (though not as relevant). I'm assuming your nature is timid, since that wasn't specified :x But yeah, a standard bulky set would have drawn me much closer to voting for this. An offensive set as a check would have been cool too. Either way, nice submission, but not quite the kind of mega-gengar I'd be using
GateCreeper's Mega-Salamence: Gotta admit that it does the job, but not really all too great at all outside of stall so not really much else for me to say here
Fire Fist Ace's Hippowdon: Now this is the kind of creativity I could get around. Even without curse, It makes for a really great counter which doesn't struggle much either with other physical threats. Same deal with aegislash, only reason I didn't pick this is because p2 is GOAT