So, after much discussion with Cam, I eventually realised I had
vastly misunderstood his base issue with most anime. Asides from things like tropes and genre etc, the main problem is certain specific kinds of sharp vocal sounds, which affect him on an almost physical level, and just happen to be especially common in anime, especially the sort with lots of over the top shenanigans and exaggerated expressions. Since I am not sensitive to that sort of sound I am not likely to notice if it happens, and even dubs might do it too, so we decided he really is better off just avoiding anime unless something seems
so appealing he's willing to risk some discomfort.
But! Discussing what he likes tropewise that I've seen in East Asian live action (since he hasn't explored it much) got me to rec my favourite romance kdrama, Coffee Prince, and while Cam thought that sounded a bit too mundane for his tastes looking up the show and actors led him to watch the trailer for Goblin, a kdrama I had never heard of. And based on the first episode he LOVES IT.
Me: It sounds like it might have a tragic ending, that's pretty common in kdramas and one reason I don't watch many.
Cam: Oh I am SURE it's going to be tragic in the BEST WAY, it's about an angsty immortal who wants to die :D :D
Me: Ha ok we really do like different things. Have fun :)
So! Have a (qualified) rec from Cam.
(Note: This is NOT the gay Chinese Guardian, it's a het kdrama)
He also really loved the scifi kdrama Moving, which apparently has some really sweet romance along with badass superhero action.
So while my attempt to find him anime he liked didn't succeed at
that, it did help him find
a show, and hopefully someone else reading found an anime they might like.
And yes I have now recced him Hotel Del Luna, since I know that's another highly regarded kdrama about an immortal, and he said the gender dynamics with a female immortal/male mortal look fun. I poked
skygiants kdrama tag and she DID review Goblin I just forgot about it, oops. But I also found Tale of the Nine Tailed which looked promising, in terms of modern day fantasy about angsty immortals.