Some more suggestions about some of the mega pokemon...
Mega Gallade from A+ to A
Mega Gallade was once a contender for the S rank slots. However, things have changed. Mega Gallade suffers from a horrible case of the 4mss, wanting to run swords dance, close combat, zen Headbutt, knock off, shadow sneak, will-o-wisp and taunt. However, it must sacrifice three of those moves, and close combat and zen Headbutt are pretty much mandatory, and the inability to KO psychos with shadow sneak is pretty horrid, so knock off is a pretty much a must. Also, it's is easily counterd by mega sableye and physically defensive unaware cleable, so it can't beat stall like some of the other megas can. Finnaly, it has poor physical bulk, which is never good for a set up sweeper.
Mega Lopunny from A+ to S
Simarly to Greninja, Lopunny destroys offensive teams with fake out, which allow it to get chip damage to score some crucial KOs. It has powerful stab moves, good coverage with ice punch, and amazing utility with Subsitute, encore and most importantly healing wish. It should also be noted that when in its base form, it cannot be paralysed by Thunderus becuase of limber. It also does well against all other play styles, no matter the match up. The only issue I find is it wants to run more then 4 moves. Lopunny would like to run fake out, ice punch, frustration, high jump kick, Substitue and healing wish. However, this offers lots of freedom as the only moves "mandatory" for the bunny are frustration and high jump kick. Need coverage? Ice punch. Want to give other pokemon a second chance? Healing wish. Want to torture stall teams. Substitute. Murder offense? Fake out. Lopunny is relatable to Azumarill right after the mega Mawile ban, where it was amazing and very defining.
Mega Sableye moves from A+ to S
My second Favorite mega evolution (first place is Altaria) and the back bone of stall, mega sableye is a force to be reckoned with. It's calm mind set has very little answers, and it can pick team mates to handle them, such as jirachi for mega Gardevoir, and skarmory for Lopunny. Magic bounce and recover make this thing very hard to take down, and it can cripple physical attacks not named mega Gyarados and are not fired type with will-o-wisp. While the meta is a little prepared for it, it still pulls its weight in all battles it partakes in, as stall is the dominant playstyle and mega sableye is the primary reason for that. Magic bounce also means that it can not only stop hazards from being set, but also block its teammates hazards from being span away. Easily one of the best pokemon in game, and I see it on the same level as latios and landerus.
Mega Diance moves from A to A+
Anyone who's has faced it knows that this thing does not leave any wounded. It has access to two great boasting moves. Rock polish and calm mind. The former make it deadly for offensive teams. While the latter is a night karen for stall. Magic bounce means it can stop hazards from being set, and it being paralysed by stuff like Thunderus. Moon blast hits like a truck, particularly if boosted. Finally, dimond storm allows diance to boost its Defense while doing good amounts of damage, making it difficult to take it down using priority. Overall mega Diance is a amazing pokemon that definentley deserves A+.
Mega Latias stays in A
It's still very difficult to take down and while the calm mind set is walled by dark types ( and most teams have one) it can still be effective the right amount of support. The bulky Defog set is much better in my opinion. It can also make a decent offensive Defogger, but normal latios is much better at this. Its definentley borderline between A and A-, but I am kind off leanings towards A rank.
Mega Sceptile from A- to A
This thing is great against offense, due to its speed tier and substitute. It also forces electric types to choose carefully, as it can switchin a and gain a special Attack boost with lightning Rod. Similarly to mega latias, I can see it in A and A-, but I am leaning towards A, becuase it's great against offense. However, it is pretty weak so I think so it can only threaten the team if it's absorbed an electric type Attack or if the opposing team is weakened so yeah...
Mega Camurupt from C+ to C
It's powerful... But slow and has two horrible weaknesses. The only jse form I see are trick room and mabee a volt turn check. That's it. Their are better megas to use. It would be much better if it could hold a life orb.
Mega Pidgeot to C+/B-
No Gaurd hurricane... this thing is great with support. If you are able to sustain your health, remove rocks and take out threats such as heatran and Tyranitar, mega Pidgeot is deadly. I've been using it along side Nasty plot + baton pass celebi. If you want a more detailed explanation, please read Recreant's post a few pages back.
Unrank Mega Steelix
Completely outclassed by Mega Aggron
Unrank Mega Audino
Outclassed by Clefable, uses up a mega slot, to passive and everything else that has been said.
Other stuff:
Mega Beedrill to B+
Hydreigon to C+/B-
Mega Gyarados to S (mabeye?)
Thunderus to A+
Mega Absol to C/C+
Exploud to D
Ditto to D
Unrank:
Shuckle
Blissey
Diance
Jellicent
Salamence
Metagross
Cloyeter
Melloeta
Gorebyss
Flygon
Venomoth
Tornadus (mabeye?)
Thunderus Therian (mabeye?)
Also, what do you guys think of reuniclus? It seems to be a decent trick room pokemon. It has good bulk, two excellent abilities, a decent movepool and a reliable recovery. Should it be ranked? If so, I would say D or mabeye C-.
Oh and un rank espeon. It's horrible.