With the Megas I'm disappointed in stat-wise, I feel a lot of these are gonna come down to what ability they get.
If Mega

doesn't retain Nasty Plot in Champions, it'll disappoint me the most. It's gonna need a bomb ability to make up for the fact it's worse than

in every way other than Speed (and that latter could hold Choice Specs...).
Mega

gets +20 in everything? Why even bother with Attack, dude? At least 126 Speed is cool, it outspeeds

by one point.
Mega

might genuinely become the worst, lowest-ranking Mega of all time unless its ability comes in clutch. With these awful stats, the ability better be broken, like a Yawn on switch in or something lmfao
I cannot take the "worst Mega" comment seriously when Mega Audino exists and the fact Mega Malamar will almost certainly retain Contrary. Is going to be amazing? No, definitely not. But if I decide to bring Mega Mala to an OU match it will probably more consistently accomplish things than Mega Audino.
You see, I'd actually rather use Mega Audino. Has a significantly better defensive typing that doesn't make it 4x weak to U-turn, has much better bulk, and can Wish-pass to a teammate. It can even stay as base Audino in the early-mid game to take advantage of Regenerator pre-Mega, making it a great Knock Off-absorber. Mega Malamar in its current ability-less state comes nowhere close. Again, it's gonna come down to the ability, but if that ends up subpar, that's gonna be a yikes for me.
Mega

will also need a cool ability to stand out from Mega Venusaur. It's harder-hitting, but the power is meaningless when it's frailer and slower. Honestly, I kind of expected it to have the stat spread it ended up getting.
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Now, onto the megas that DO interest me:
Mega

sounds so much fun. STAB Body Press off base 172 Defense, plus Iron Defense, is going to make Mega Chesnaught hit like a freight train. Combine this with Leech Seed + Spiky Shield, or Synthesis, and this'll be a tough nut to crack. The lower Speed kinda sucks for singles, but I can see this being a monster in doubles on Trick Room teams.
Mega

is very likely getting Pure Power, or a Starmie equivalent to said ability, and that makes Starmie probably my personal favorite. Not just because Pure Power is a strong ability, but how different it changes Starmie's playstyle as a whole. It's always been a fast Special threat ever since RBY. If it's base 100 Attack in Champions, it's attacking stats will effectively be 218 Attack and 130 Special Attack, with 120 Speed on top of that. Flip Turn in rain will go so stupid. Has the capacity to run mixed sets to deal with physical walls, and if it ends up keeping Bulk Up in Champions, it can be an awesome physical sweeper, too.
They could also pull the funniest shit ever and have Mega Starmie be the only Mega of all time to have over 100 points added to its BST, and run a different ability.
I love this goofy weirdo, strangely reminds me of the final majora fight in majora's mask
omfg, I love this thing
I appreciate Mega

and Mega

in a similar way, in that they can utilize their base forms pre-mega to make the post-mega stage much stronger. Skarmory has Weak Armor to boost Speed by 2, along with Swords Dance. Scolipede on the other hand has Speed Boost pre-Mega. Although I do fear this'll make Mega Scolipede strapped for move slots, since it'll want Protect to guarantee a boost, I feel it'll be better without Speed Boost compared to Mega Sharpedo, who isn't nearly as bulky.
Mega

just on the premise we can finally use this legally.
Mega

being a base 140 Attack Shell Smasher will definitely be scary.
Mega

sounds like a Fire-type Mega Alakazam; a fast Psychic-type Nasty Plot demon. Delphox also gets Expanding Force in SV, so while I can see Mega Alakazam giving it competition, Delphox stands out by blasting through Steel-types more reliably, much like Armarouge.
I'm going to end this post with this iykyk:
