Doctor Doom & Kang the Conqueror.
I'm a ways off from starting Kang, though I've some ideas... and I've been running Doom over in my head the last few weeks.
Until last night:

Obviously not finished. A converted Iron Man skin, using elements from another:

But I've a workable player skin for a bot to watch as I work out what I'll do next to it.

Mostly the nose is where my largest challenge will be.
Obviously the Male Soldier model doesn't lend itself well to a character who wears a hood, or a cape for that matter. I've been basing the look for my edit off various versions of the character in comics, as well as the action figure from the Secret Wars series.