Reading that scene where Claude freaks out about what Peter said, i thought to myself - that's it. That's who Claude reminds me of. Fanon Snape. That scene, right there, i've read again and again between mentor!snape and student!harry where harry gets sort of familiar and says something that snape almost completely misinterprets, and there is fallout. And sex, usually.
Not to say you're unoriginal or that i don't love your Claude! But it came to me in a flash - claude is snape! Now i feel like a weirdo.