This is a complex question so let’s examine a few scenarios.
Corrupted or Otherwise Touched By Terrible Powers From Beyond: Eh, nobody’s perfect. If pressed, would admit this is actually kind of a bonus.
Ridden By Symbiotic/Parasitic Spirit: Depends on the being, how tractable it is, if it’s always listening in on conversations, etc. Potentially awkward or dangerous. Not a dealbreaker. Again, shit happens and we’re not put on this earth to judge (mostly).
Literally a Demon Driving a Corpse Around Like A Car: Ill-advised, also extremely unsanitary. Still not quite out of the regret-later zone and into the no-fly zone I’m afraid, not that he would admit this out loud.
Actual Demonic Manifestation or Vision: What happens in the nightmarish hellscape between dreaming and waking stays in the nightmarish hellscape between dreaming and waking. Mostly. Hopefully. Rin absolutely knows better than this, which tragically does NOT mean he won’t.
Ashkin: Again, unsanitary and deeply socially unacceptable, but if they’re human-like enough to inspire romantic affection then possibly worth keeping in the list. I mean, that guy who plays Triple Triad out in the desert next to where all the mythril nodes are seems pretty nice.
Advanced Mammet or Other Construct: Would probably result in an immediate termination of the relationship in favor of figuring out how it’s made.
One Of Those Ishgardian Vampire Warlock Guys From The RDM Quests: Rin is more likely to date one of these guys than a regular Isghardian, let’s be completely real here.
A Dragon: I mean they put up that big mural in Falcon’s Nest of this, it can’t be that bad.
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