@JoshieOkay, I've been thinking a little about Ian's heritage, and realize that he probably would have a few more natural quirks from being the son of Asmodeus that he;d have to keep a handle on. First, his saliva has two different kinds of poison. The first is a semi-potent Aphrodrisiac, enough to make people feel hot under the collar, but that's about it. The second type is an anesthetic of some power, not strong enough to knock someone out, but it can make someone feel real drowsy and disoriented(Ian uses it to avoid having to 'run the bases', as he's not as comfortable with stuff beyond kissing as he likes people to believe). Both of these poisons are only produced if he's feeling aroused(in the physiological sense, meaning quickening of the heart, sweaty palms, etc. etc.) He can switch the type of poison he produces by thinking on it, but the aphrodrisiac is the default. These poisons increase in potency when in demon form, are always active, and can be injected through his fangs directly into the blood stream for even greater effect.
Second, Ian also has some enhanced pheromones of his own, but it's more like a demonic aura than biological, and only has an affect on humans, while the other poisons tend to wok on anyone. However, given his half-human state, he keeps it turned off because A)it also affects him as well, and B)the less demon stuff he has to worry about, the better.
Third, and this one is a bit more generic demon stuff, he heals faster than humans by a good amount. Not wolverine levels, though, more like an injury that keeps regular people down for months, only keeps him down for about 3 weeks, perhaps one whole month. He also is resistant to most diseases as well.
Finally, and this one Ian doesn't know about, is that Ian can change his gender and appearance. Not at will, mind you, but according the desires of a human being. His body does so overnight as he sleeps, and to change back requires him to drain a relatively small amount of life energy, either through a kiss or 'other' methods, and use that to change back via another nights sleep.(the initial change takes some of his own, though it's not a lot.) Basically, if anyone near Ian, or Ian himself, wishes to change his appearance or gender, they'd have to think that while touching him, and the next day, it would happen.
Also
@Tengri*echoes from everywhere* "Hahahaha, you think you can make me do stuff. Also, I've sent you a brand new set. This one involved you, Swarm,
and her bugs. Enjoy!" *que echoey, demonic sounding laughter*
As for Nucleus, makes sense. Plus, her ability over bugs means that she can be a lot more sneaky than a rather show-off demon boy.