I think the high heels on the boots, the neckbuckle (which screams BDSM) and the black-feathered/furred boa ruined it. The armor wasn't that bad. I'd still take the single-pauldron brown armor and blonde hair and conan boots from the original design instead (anyday).
And on top of that... he bears no resemblance to the other Belmonts at all. XD Even Juste looks like Leon, but redesigned Simon?
I don't know. If you ask me, the Trevor from CoD was the best example of what a Belmont should be. He was buff, but not overly muscular and his clothing reflected the times.
Trevor has one of the best Belmont designs Kojima came up with for this reason, imo. When I first saw her design for him I was like...

Regarding an incubus, he should be a "pretty boy". After all, if an incubus is the male equivalent of a succubus (as we all know) then he should be attractive to women and from what I know, most women like pretty boys.
I agree. He shouldn't look like a 'pushover,' though... there should be something about his design that exudes danger.
Maybe he could wear a black loincloth with boots and gloves, and have tattooos marking his body? Maybe throw in a black leather armband or two.
That sounds like what Isaac form CoD would wear to bed. XD
... Well, you know how the succubi are often disguised in these games? Like the succubus in LoI? The incubus could start out disguised as a human, perhaps robed/cloaked.
I imagine it would wear something like a cross between these two:
http://niekra.deviantart.com/art/As-you-wish-M-Lady-For-Suza-43618298?qj=2&q=boost%3Apopular+incubus+demon&qo=504http://glasssnake.deviantart.com/art/Incubus-Colored-127871473?qj=1&q=boost%3Apopular+incubus+demon&qo=403Only the clothing should be studded with spikes. An incubus should be attractive, but intimidating... and not look like an S&M sub. Go for the dom look while accounting for the wings.