When did Richter become such a pussy? That is definitely weak storytelling. You'd think Maria would be there for him and keep him under control. Unless Richter goes the way of world fame and wanders the planet from bar to bar sleeping with ho-bags and downspiraling into inescapable depression. Thus he gets so drunk one night that he just goes apeshit and starts referring to himself in the mirror as "Wendel".
No seriously, Richter calls himself a Belmont?! Man, I thought he was cool.... 'til now.
So, you're saying that in this second wandering (goddamn this is a stretch), that he falls under the spell of a succubus, dies, but managed to impregnate her, and the succubus somehow had his human offspring.
No offense, Thomas, but that's no better than IGA's storytelling at all.
1) I don't think succubi can get pregnate (they are said to impregnate human women though (by collecting the essence of the man), thus creating a surrogate mother, but that'd require too much explanation, or assumption for IGA to handle)
2) Succubi suitors die on impact, (or even entry XD)
3) Castlevania's description that they "invade men's" dreams, is just a euphemism in place of the fact they kill by having sex with them. Although some say the desire for them arises from dreams. It's really all just an excuse as to why men lust after girls, and a church's little tale about why they shouldn't.
Most ideas for any demon was started at the behest of the church's desire to have control over their subjects and to force religious barriers between what they considered sin, but what actually just turns out to be human instinct.