Following
drampa's grandpa observance on the ZA megas, I will be listing all the others (with permission).

95/80/93/135/110/70
Ability: Magic Bounce
Mega Clefable could be an interesting threat in the meta, possessing a Fairy/Flying typing, a respectable special attack stat., and a great ability. Not the best speed stat, but it could work on TR teams.

80/125/85/135/95/70
Ability: Innards Out
Victreebell could be a good suicide lead, trading for a setup sweeper. It only really gains Leaf Blade, Ivy Cudgel, and Malignant Chain (which is a lot actually) with similar attacking stats to Mega Clefable, being able to run a mixed set if possible.

80/92/115/143/115/80
Ability: Mega Sol
Mega Sol is a good ability, giving a permanent Sunny Day, which gives you one turn Solar Beams and a free Fire type move. Not much else to say about it other than that, though.

85/160/125/89/93/78
Ability: Dragonize
Poor Feraligatr gains literally next to nothing it terms of moves, besides maybe Wave Crash. Double-Edge is the only decent move boosted by Dragonize. Feraligatr has some things going for it, though, like a massive attack stat and decent bulk. Oh yeah, it has dragon dance too.

65/140/110/40/100/110
Ability: Stalwart
Stalwart is going to be useless in singles lol. However, it’s going to be a beast offensively with Dragon Ascent, Double Iron Bash, and a pretty decent speed stat.

75/50/110/135/120/65
Ability: Levitate
Chimecho… um… I have no idea what to say about it. Great defensively and as a TR attacker, but that’s probably about it.

70/80/70/140/100/120
Ability:Snow Warning
A possible threat in the meta, with its great Special Attack, Speed, and tools like Snow Warning, Blizzard, Moongeist Beam, and Aurora Veil to gain good bulk.

110/148/75/110/110/75
Ability: Mold Breaker
Ogerpon-Hearthflame should watch out, or not. Jokes aside, Mega Emboar could be decent. It gets Mold Breaker, Pyro Ball, Collision Course, with pretty decent stats. It’s bulk is rather underwhelming, however.

110/165/100/65/65/103
Ability: Piercing Drill
Ah yes, Excadrill. The poster child of Sand teams (along with Ttar) since it’s been on Sand teams since it was first introduced. It doesn’t get a great sand-beneficial ability, but it does have menacing stats, hitting hard and an ability that allows it to hit through protect with STAB moves like Sunsteel Strike, Drill Run, High Horsepower, Iron Head, Headlong Rush, etc. Even without protect, it has Precipe Blades.

60/75/110/175/110/90 (Chandelure)
Ability: Infiltrator
85/159/105/70/105/55 (Golurk)
Ability: Unseen Fist
Chandelure has a massive Special Attack, Moongeist Beam, decent speed, and good bulk. Mega Golurk, however, I like it but not a lot. I don’t like it. It’s slow, it lost No Guard, Rage Fist is restricted, I just don’t like it.

75/125/77/133/81/142
Ability: Protean
Mega Greninja feels the exact same as its non mega form, except with boosted stats. It has somewhat decent attacking stats, a high speed, and it’s normal frailty. It could (key work being could) be strong, like the next pokemon I’m going to mention.

74/85/87/155/148/102
Ability: Fairy Aura
As far as I know, Fairy Aura has never existed in a STABmons metagame. It doesn’t gain anything that great, but it still hits super hard with Light of Ruin and Moonblast. Could be one of the best mons in the metagame imo.

97/157/122/62/107/33
Ability: Iron Fist
If you’ve seen Wolfe’s video where he and Alpharad build a team around this mon, you would know how much they glaze it. Part of the stuff they do say though is pretty true. It does work well inside TR and it has decent bulk. I’m not sure if it will be great here though.

83/90/105/150/96/101
Ability: Adaptability
This thing is going to be a monster. Malignant Chain is already good, but Glimmora’s monsterous Special Attack and its ability take it to a whole new level. It has a good speed stat and will probably become a nuke to anything slower than it. Not to mention that it has good coverage moves too.

60/135/95/90/95/110
Ability: Electric Surge
View attachment 841624

60/100/55/160/80/130
Ability: No Guard
Raichu Y is going to be insane in this format. Stab-wise, it doesn’t gain many good options, but with its move pool and stats, I think that Rai Y will be amazing in this meta. I don’t think that it will last being legal for long.

85/80/145/90/135/80
Ability: Eelevitate (Levitate and Beast Boost in one ability)
Eelektross has never really been that great. With this mega evolution, it could actually prove to be viable. Not a top threat, but still decently good.

65/85/105/132/165/44
Ability: Regenerator
I’m scared of this thing. I’m truly scared of this thing because it’s going to become a staple on stall teams, with Flip Turn, Mortal Spin, Dragon Tail, and whatever other move you think of that could be good on it. Toxapex is already a big threat in this metagame, getting even better with another stall member to toy with your opponents. Be prepared.

65/135/135/70/65/100
Ability: Defiant
I like Mega Falinks. Since when was Defiant ever a bad ability? It gains Thunderous Kick, a pretty good move, and is the only one to have No Retreat. It may not be great, but hey, it might have some niche, right? Also a possible counter to the next mon I will mention.

65/130/135/55/135/68
Ability: Intimidate
Get countered by Falinks L-Bozo… I mean uh… it serves as a pivoting Intimidate user, something that Incineroar could never be in this format. It also has good bulk, barring 65/135/135, which is pretty respectable.

85/140/100/60/90/110 (Staraptor)
86/102/88/98/120/88 (Malamar)
Ability: Contrary (both)
Man these two get a lot of different moves to be affected by Contrary. Staraptor gets Close Combat and Superpower and Malamar gets Superpower and Psycho Boost (I don’t think it gets Close Combat.) Malamar will definitely be more diverse, being able to run mixed sets, and Staraptor can output massive loads of damage. I look forward to seeing how these two affect the meta.

New Ability: Justified
I know Mega Gallade isn’t new, but I had to include it since it got a new ability. It still sucks and gets outdamaged by its non-mega counterpart.

78/85/110/160/116/36
Ability: Beserk
@drampa’s grandpa didn’t give a full analysis, just that they thought it was perfect. I could see why. Beserk is a really cool ability, further amplifying its already high Special Attack. It’s rather slow, but its other stats help to moderate that.

86/88/92/129/86/126
Ability: Fire Mane (increases damage of fire moves by 50%)
I don’t have much to say. It has a pretty good speed stat, but that’s probably about it. Also I did it last because I forgot about it lol.

60/140/149/75/99/62
Ability: Shell Armor
Bug Poison isn’t a great typing per say, but it doesn’t get Mortal Spin, so it could have a use as a spin user.

72/140/130/64/106/88
Ability: Tough Claws
This thing is going to be disgusting to face. Shell Smash? On a Tough Claws Pokemon?
Now you’re just asking for trouble. It gets Stone Axe, making it even more annoying.
Will include a VR later on a different post