Is it okay to use another player's character 'fantasia' as your own without asking?

[Berethos]

I'd only get bugged if they pretended to be me.

Same.

Though being a twin in real life, I'm very much accustomed to their being someone else out there that looks exactly like me as it is.

So yeah, if someone copies my look I'll probably be flattered, but pretending to actually be me is obviously off limits.