FB Mewtwo on gym offence

It's nested between machamp and metagross. Higher DPS than metagross, but less bulk, and lower DPS than machamp but more bulk. Blissey almost always carries DG because its a much better move than Psychic

Personally, ive preferred metagross or machamp because their two bar moves, and powerful one bars might be worse because of the lower HP of the defender.

Slaking carries play rough most of the time, as earthquake is a bad move and if demotivated, a machamp might be able to KO it before it can even use a play rough

Metagross is part psychic, so it takes neutral damage from fighting, Meteormash/Psychic as double charge moves deals with those fighting and poison types and other gym defenders, and FB/Psy mewtwo is better against poison types, but very expensive.

I no longer have fb mewtwo in my gym squad, because I found I wasn't using it. A machamp and a metagross can take care of all of the big normals in a gym. The other four mon in the squad can take care of whatever is left. Mewtwo was a bit glassy, and not as good as machamp for this purpose.

Mewtwo will be the tankier option in the first two scenarios, but Machamp will always be the faster option. So it really comes down to personal preference. If you'd rather save potions/revives, go with Mewtwo. If you're looking for a faster clear time, go with Machamp.

Personally, I haven't been using my FB Mewtwo as often as I thought I might. It has some great utility since it has both charged moves unlocked and SB/FB gives it a lot of flexibility as an attacker. That said, Machamp has remained my go-to option against the Normal-type tanks due to faster clear times, though dodging DG from Blissey and PR from Slaking is a must. I unlocked Rock Slide for him if I'm feeling too lazy to swap attackers against a partially demotivated Togekiss, Dragonite, etc, which has made Machamp an even more valuable gym attacker imo.

In the event that I want to bring in an attacker that can tank hits, I'll usually default to MM Metagross.

Personally, I prefer using PC/FB Mewtwo to sweep gyms. I've tried using both Mewtwo and Machamp against gyms with multiple big normal types, and one Mewtwo can almost always chew through a Blissey, Slaking, and Snorlax, whereas the Machamp is almost certain to faint out before defeating all three. This is partly due to Mewtwo being tankier, and also due to psycho cut being easier to dodge with than counter. It takes very few dazzling gleams or play roughs to take out a Machamp, whereas Mewtwo can tank a few, and still keep fighting.

What was once at least worthy of debate for me is now a no-brainer, because with the addition of second charge moves, I now have a maxed psycho cut Mewtwo with both focus blast and shadow ball. I believe this is the best generalist gym sweeper in the game.

Metagross is a great gym sweeper as well, but it doesn't seem to be super effective against as many defenders in practice. But certainly, if I'm taking on a fully motivated gym with tough defenders, which will likely require more than one attacker, Metagross will have a place in my lineup. I consider it roughly equivalent to DT/O Dragonite or Rayquaza, in that it outputs reliable neutral damage against most defenders.

I use a PC Mewtwo with both Shadow ball and Focus Blast to clear gyms. Shadow ball works for clearing out anything not Blissey/Snorlax and Focus Blast works for taking those out.

I, like some other commenters, do have a maxed PC/SB/FB Mewtwo, and have used it somewhat in gym battles. For me, it ranks around Machamp, maybe lower. Psycho Cut is nice for dodging, but the damage is so low that you have to rely heavily on charge moves, whereas Confusion is great for damage between charge moves, but makes you far more likely to get caught by a charge move from a hard hitting defender like Dragonite, Metagross, or Slaking. In my opinion, for general gym clearing, Metagross is by far the best. Save for Earthquake, it can shrug off the charge moves of the top gym defenders; Bullet Punch is a nice balance between dodge-friendliness and damage, and Meteor Mash is fantastic. If I'm battling a gym before a raid, I try to use my fastest counter to each defender - i.e. Machamp for Normal tanks, Mamoswine for flying Dragons, etc. - and so many of my general gym battlers are underused anyways, over specific counters to specific defenders.

I like machamp over mewtwo. I’ve tried both when someone was using goldens on a gym. Machamp is noticeably faster in taking down the big defenders but like others said it is more glassy although I seldom get hit by a charge move. So I usually have 2 on my attack team, one has heavy slam as a second move for fairies and the other has rock slide to take out many others that resist dynamic punch. I also love weavile over Mamoswine because of its speed

So many differing preferences. I go for speed (dps) because I’m always having a surplus of max revives to use and also I like to take the gym as fast as possible

I needed to be honest with myself and remove FB as second CM from my best Mewtwo, as I simply didn't find a moment when I would prefer to use him over Machamp, Metagross and now Mamoswine for gym sweeping. I bought RS as 2nd CM for Machamp and not it's basically all I need too.

In my experience, IB or TB work well for PvP coverage in Master League against Kyogre or Groudon, so I just switched to that for the time being, and I will certainly give it Psychic whenever a relevant raid requires it. Other than that, I'm quite sorry, but my Mewtwo is mostly a 2nd choice for raids where I don't have a team of 6 maxed supreme counters (a good 2nd choice, let's be fair).