Mega Evolution Theory

Ok so remember how Charizard and Mewtwo got two megas?

Well, what if I were to tell you that they have a strange connection that may give us a hint into solving mega evolution?

Let's start with Charizard, Mega Charizard Y retains it's original typing and is essentially a slightly modified version of the original in terms of design though it does seem a bit closer to Charmeleon, whereas Mega Charizard X switches the lesser typing (Flying) for a better one (Dragon) and dons a new colour scheme, as well as some other things making more like a dragon type.

Then we have Mega Mewtwo, Mega Mewtwo Y stays a pure psychic type and becomes closer to the original Mew in design. Mega Mewtwo X gains the fighting type as well as having many alterations to adjust it to this type.

Notice the coincidence? The Y's slightly modify the design with nothing drastic (no new type, etc) and the X's gain or trade a new type and become altered to accomadate this.

Xerneas is the Pokemon of life, breathing new life into the design.

Whilst Yveltal is the Pokemon of Death, bringing back elements of past evolutions.

So based on this if other pokemon were to gain an additional mega it would either be an X or a Y based on the design of the original.

A few X's based on this - Venusaur, Blastoise, Blaziken, Aggron, Rayquaza.

A few Y's based on this - Sceptile, Swampert, Altaria, Ampharos, Lopunny.

Sorry this was so long.