...and no discernible drawback at all, actually.
"Regeneration comes with... no discernible complement," he reports. "Okay... after it's all done with these crossbow bolts, we can find out whether you can undo it. In case the answer is 'yes, but then you can't do it again'."
"Right. So there's at least one more horrible thing of some kind waiting for us to stumble across it, I suppose. Do you want me to pull the bolts out...?"
"The magic seems to be taking care of that by itself, and they're awkwardly placed for that sort of thing; too much messing around in that area and I might end up bleeding more than I'd like."
"Okay. ...The good news is that if I can undo it and redo it it's almost certainly consistent, you could try out any of the magic I've got and not have to live with the effects forever, but it'd probably be good to save for emergencies in case you got 'suddenly transported to a random location' or 'magically in love with me' which might... not undo as easily."
A crossbow bolt falls from his shoulder. He makes a slight face. "This is painful and unsettling. I suppose I shouldn't complain; it is still better than not having access to magical healing."
"If you can turn it off and back on again... I'm wondering whether I prefer to keep it indefinitely or not. It would make fighting darkspawn a whole lot easier, but I don't want both of us to be simultaneously incapacitated by the lurking drawback. Maybe I should refrain from going around with it on habitually, but take it up before any fights we get into."
"I'm not sure it's fast enough to be obviously a good risk during a fight, but I can patch you up after..." Pause. "There's no darkspawn blood on your hand anymore."
"Huh," he says, looking at his hand. "I suppose you disintegrated it."
"Do, um. Do you want me to disintegrate the rest of it."
"That... seems likely to get really awkward without actually leaving me clean enough to feel comfortable again."
"...Should we discuss the potential ramifications of you being magically in love with me, or continue avoiding the subject?"
"Um." She averts her eyes, although they weren't actually properly focused on him in the first place. "...whichever you'd rather. Maybe with a bias in favor if you're going to want to try out more magical powers. And a bias against if discussing it means I will have to tromp through a stressful survival situation having confronted particularly distressing relevant possibilities."
"...well," he says. "I am frankly not capable of entertaining romantic thoughts while crusted in weeks-old darkspawn blood. But I haven't observed anything that disqualifies you out of hand. So if particularly distressing relevant possibilities are going to come up, it will be after I have saved the world and had a bath. I hope that's more reassuring than otherwise."
"Good. As for the bias in favour if I'm going to want to try out more magical powers... yeah, I see the logic. And I can imagine wanting to try out the ability to disintegrate darkspawn on contact, for example. So - what can you tell me about the experience of being magically in love?"
"Because I could see it being awkward? And we've been mostly avoiding awkward."
Nod nod nod. "Um, more or less as soon as I could orient myself enough to identify your existence via a combination of language thing and weird sense thing you were suddenly intensely important. I can... think around it, pretty much, but I have to try, and I can get some mileage by observing that you do not seem to be a particularly selfish person and would therefore not endorse various ludicrous tradeoffs I can imagine feeling emotionally compelled to make in your favor, but again I have to try. I'm not actually sure what would happen to me if you died and don't want to find out. Um, it's sort of hard to regulate my attention - I can do it, especially looking out for darkspawn that we need to know about because those are dangerous, but if we were somewhere safer I could probably just - kind of - not think about anything else for hours on end."
"That sounds really inconvenient on a number of levels," he says. "Especially under the circumstances."