It's Victor Vale from V.E. Schwab's Villains series (wow, that's a lot of v's). His asexuality doesn't play a massive role in the books, though.
Oh, I forgot, there's also Alice Oseman's YA contemporary book Loveless, which is the coming-out story of an aroace teen. I don't read YA all that much anymore but once I heard about it how could I not read it.
I have a bunch of other books with ace characters on my TBR, but who knows when I'll get to them