Since Tyranitar, Salamence, Metagross and Garchomp all received Mega Evolutions, I think it'd be fair if the rest of the Pseudo-Legendaries were to receive Megas before Gen VI concludes, in my opinion.
Let's start off with...
Mega Dragonite
I have quite a few ideas for it. To make it unique from Mega Salamence, it should become Dragon/Water for typing variety reasons. As for it's Ability, Multiscale is the route to go. I also reckon it could receive an Ability that can convert Normal Type moves into Water Type moves. Then I thought No Guard can also be great, as Dragonite has plenty of low accurate, but very powerful moves to take full advantage of that Ability.
It should gain increased Sp. Atk and Speed, as well as a small buff in its' Attack and Defences. Plenty of options to choose from with a possible Mega for one of Kanto's best Dragons.
Appearance-wise, it can try it's best to be as long and majestic as it's pre-evolution. I can see the tail becoming much longer, as well as some blue pearls and a cool beard to go along with it.
Mega Hydreigon
The mon seems balanced, but a Mega should do no harm to it. It should remain Dark/Dragon, but like Mega Dragonite, there are plenty of options for its' Mega, at least in my opinion.
Judging by its' movepool, and to be a monstrous threat it deserves to be, it's new Ability can either.
A. Be a new Ability to convert Normal Type moves into Dark Type moves, to take full advantage of moves like Tri Attack or Hyper Voice.
B. Contary is something, as it has a STAB to take advantage of with that Ability, but I think that's way too much to ask for what is an already dangerous Dragon Type and an already unbalanced metagame.
Or C. If you feel as though B is too much, even though I just established it, then you're free to suggest whatever Ability it rightfully deserves when it does get a Mega Evolution eventually.
As for it's appearance, I think it should be some intimidating dragon cyborg thing, or something like that.
And last, but not least...
Mega Goodra
Goodra definitely deserved just a little more when it comes to defensive and offensive usage.
To make it a dangerous healer, it should gain Regenerator. That will really help the cute slimy Dragon be a threat. It has decent offenses, so it's Attack and Sp. Atk should be equal to allow some defensive support. It's typing should be Dragon/Poison to help it properly stand up to dangerous Fairy Types like Sylveon, Florges, Togekiss and Xerneas.
It may not be easy to picture, but it can grow some slimy whips on its' arms and back. I even think it can grow a second and slimier tail, but mainly to use it as a whip.
If you have better ideas for those guys, you're more than welcome to share them.
