> M-Tyranitar -> Goziratar
Gojira + Godzilla + -tar, to fit the line's name suffix.
> M-Aggron -> Eviscerron
Eviscerate + Iron
> M-Venusaur -> Gaiusaur
Gaia + -saur, to fit the line's name suffix
> M-Charizard X -> Charidrake
Char + Drake, referring to its new Dragon type
> M-Charizard Y -> Chariscorch
Char + Scorch, referring to its Drought ability
> M-Blastoise -> Armastoise
Armament + Tortoise, could also be Army or Armor
> M-Gengar -> Phantaze
Phantom + Gaze, or even Haze, but Gaze would refer to its Shadow Tag ability, as it is essentially like a Mean Look. Also sounds a bit like "fantasy", only a little bit.
> M-Alakazam -> Hocus Pocus
Another magician's incantation.
> M-Kangaskhan -> Kangaskin
Kangaroo + Kin, referring to mother and child fighting together
> M-Pinsir -> Soarir
Like Pinsir is to pincer, Soarir would be to soarer, as M-Pinsir soars in the skies with its new wings.
> M-Gyarados -> Skullkraken
As a reference to its original concept name.
> M-Aerodactyl -> Terrodactyl
Terror + Pterodactyl
> M-Mewtwo X -> Mewtaint
> M-Mewtwo Y -> Mewtense
Mew + Taint, sounds like mutant
Mew + Tense, often when you're feeling tense you can't sleep, referring to its Insomnia ability
...I tried.