// let's mega-evolve!

If there was a Mega Delphox, I think it'd still be bipedal. Even though real-life foxes are usually four-legged, as Fennekin evolved it began to stand and be more humanoid. I'd imagine its mega would remain the same as it'd be weird for them to transition like that and just... flop back down, haha. And yeah, I agree that there aren't exactly many sixth gen mega evolutions so working on a starter mega first would be the smart move. It'd be popular amongst fans, well-known and an easy pokemon to design off of.

I've never been particularly good at imagining mega evolutions but I'd say adding more fire to its design would be nice. From looking at it, you can only assume the orange means fire while its really obvious that it belongs to the psychic type with its robes. So having flames or anything that really puts emphasis on its fire typing would be great for its mega evolution. :]

Yeah, introducing mega-evolution forms for starter Pokémon would indeed be a good place to start, since they're arguably more known among fans than others.

For us all, here's another addition of Bimonthly Featured Mega. In this round, it's Mega-Metagross! Here are some dex entries of the Pokémon to have it started:

X - With four linked brains, it's more intelligent than a supercomputer, and it uses calculations to analyze foes.
Y - Metang combined to form it. With four brains, it has the intelligence of a supercomputer.
Omega Ruby - Metagross has four brains in total. Combined, the four brains can breeze through difficult calculations faster than a supercomputer. This Pokémon can float in the air by tucking in its four legs.
Alpha Sapphire - Metagross is the result of two Metang achieving fusion. When hunting, this Pokémon pins the prey to the ground under its massive body. It then eats the helpless victim using the large mouth on its stomach.