All of the mega's seem pretty underwhelming except for a few... but for discussion purposes(and the fact this is my first post here in forever) I'll go through them all.
Venusaur - A pretty well-designed defensive mega evolution, with the ability to actually last thanks to leech seed / synthesis(combined with weather nerfs). Poison/ Grass was never the worse defensive typing, and aggressively it got a lot better, but still not vs steels. 80 Speed with 122 Sp. Attack is also not negligible.
Charizard - As a whole, Mega Charizard as a whole needed a bit of a speed buff, but neither version got it unfortunately. Charizard Y with drought and a very high sp. attack stat makes it a pretty dangerous attacker that brings sun utility with the weakness that both inducers of drought have issues with SR. Charizard X is a better sweeper with STAB outrage + flare blitz, better bulk + typing, and Dragon Dance. It also isn't as weak to SR and priority, but still somewhat suffers.
Blastoise - A glorified rapid spinner, imo. I think we need more data on how his ability works before I can make a real judgement call on him, but he seems to just have power behind him without fixing any of his core issues as a pokemon.
Alakazam - Suffers similarly to Blastoise: does a lot of what he used to do without solving any of his issues. If anything, losing Magic Guard + sash is rather saddening for him, not to mention Mega Gengar does his job similarly.
Gengar - This guy is going to disrupt the flow of defensive teams; Ghost not being resisted by steel is HUGE, which combined with his Poison STAB makes it more difficult to wall. Blissey / Chansey have to deal with Sub/ Taunt/ Pain Split/ numerous other sets in some fashion.
Kangaskhan - Pretty interesting, but losing scrappy is unfortunate. Maybe be the only decent user of power-up punch.
Pinsir - I do not know his movepool, but his numbers say he's ok, but bug/ flying isn't the best, even with flying return STAB. Close Combat / EQ help with steels I guess, but Skarmory still stops it.
Gyarados - One of the worst megas, imo. The only thing it can do better is maybe the resttalk set with DD and waterfall thanks to mold breaker and MUCH superior defenses. Gyarados' Intimidate and flying typing actually help it more in a metagame with mega lucario around.
Mega Aerodactyl - Pretty neat, but unless he got better attacks his sweeping capabilities are determined underwhelming by the same problems, and the SR set really wants the sash and using a mega for a suicide pokemon is meh.
Mewtwo - I'm still torn. 140 speed on Y with that sp attack is awesome combined with Insomnia and no recoil, but regular mewtwo can deal more damage with LO, less speed, and not take up the mega slot. X is weird because it deals less overall damage due to his physical movepool being ****ty, but Aura Sphere does more damage on him than even LO mewtwo and he is bulkier with better defensive typing... it will be sad if the best MegaMewtwo X set is an all-special set. SubPunch maybe?
Ampharos - Cool and decently bulky with a great sp. attack stat to work from, but speed is just an issue on it.
Scizor - Bulky sets are going to love this form, but honestly Scizor is probably just best sticking with CB to the end of time.
Heracross - That attack stat is VERY scary! However, speed is just an issue on it and it can't use scarf to patch it up. I don't know if it gets more damage by trying to abuse skill link, but it seems like a rather wasted ability slot as well... T_T
Houndoom - I really like this because it's so COOL! Ghost resist is going to be big and even though this is flimsy, 90 defenses aren't the worst, so maybe...? It's gonna be fun for sun teams to try and abuse, though.
Tyranitar - On something without recovery options, I think you really need the extra leftovers. Mega Tyranitar is going to be more useful in rotation battles, where you can use the mega evolution to extend the sand stream as well as providing a good ghost resist... Tyranitar is going to be HUGE this generation because it's the only truly good defensive dark type, I am just not sure how its mega form will be able to compete for the slot of mega's.
Blaziken - ...Mega Blaziken just emphasizes everything that made Blaziken ridiculous. Maybe Azumarill will rain on its parade, but honestly aside from that we are looking at mostly the same pokemon with a buff.
Gardevoir - I think they should have made it a tad tankier thanks to the big dress, but whatever. Fairy / Psychic is pretty good typing, just it has too many problems with steel types.
Mawile - ... I think they did RATHER A GOOD JOB. Speed hurts, but a pokemon with this typing and natural attack stat is pretty cool. Problem is what it does with the turns it gains... it can be a cool SD passer that actually hurts if they try to wall it.
Aggron - Nintendo finally learned that rock type was so bad defensively it lost it entirely. I think they mistyped the name from "Mega Registeel", because that's how it looks like it will act. Obv sp. defensive isn't the best to be so comparable to, and speed... meh. You can try a rock polish/ steel type speed boost thingy to try and sweep.
Medicham - That High Jump Kick hurts! It also isn't the most fragile, so without LO wearing it down it isn't the easily to kill off, but ONLY 100 speed with no way to upset that means you have to set it up properly.
Manetric - Volt Switch the pokemon!
Banette - 165 attack shadow sneak and priority destiny bond in an attempt to go 2 for 1 seems like the best way to play it out, with priority taunt being useful as well and then some random coverage move finishing everything out.
Absol - Cool, but not really worth the slot. Too much was spent increasing its special attack which means a mixed set would be better, but not sure if it would be worth it still. Being a magic bounce baton passer is cool, though. Sucker Punch/ Fire Blast/ SD/ BP? idk
Garchomp - Lost speed? No thanks. Garchomp didn't need to hit harder, though I guess if you want to **** up togekiss you can(on the turn it comes in) mega evolve then SE it with SS going. Worth? maybe. it got some additional bulk to work with I guess, but the lost speed... just ew.
Lucario - The BEST mega evolution, in my opinion. Lucario's issues in previous generations were his lower speed and occasional inability to fit in an SD due to its fragile nature. While mega lucario is only just a tiny bit bulkier physically, it's SO MUCH STRONGER that it can literally 2HKO anything with 12.5% damage(SR vs Skarmory, Spikes vs Hippowdon). I'm going to run:
Lucario @ Lucarionite
Dark attacked increasing ability: Jolly
4 HP, 252 Attack, 252 Speed
Close Combat
Crunch
Ice Punch
Bullet Punch
Ice punch beats chomp / gliscor/ zapdos / random flying things, crunch for ghosts, and Close Combat everything else you can. No need for SD, imo.
Abomasnow - I don't know what it's attacking stats are because i read 130/ 150 on smogon and 132/132 on serebii. Regardless, it got a HUGE boost and if you want a hail team you want this monster.
