I wouldn't mind, but this character is the wrong sex. I wanted a female (with a particular role in mind as the romantic interest) and a male turns up. And a male simply will not do. No, not at all. Not even for the Version With the Serial Numbers Filed Off that it might be possible to do if I write the fan-fiction version first. Which I keep telling myself I don't have time to do, but the ideas keep on coming. I have consulted the main character concerned (for the possible re-write non-fan fiction version) and he is definitely not gay, so not interested in the new character in that way, thank you very much.
However, today I recognised this new character, the one who's male when I wanted a female. Yes, he was trying to pretend he was entirely new, but I know who he is now. He's a refugee from a long-abandoned short SF story. And if it is him, he has a twin sister. So I think that will work very nicely. Not that I'm writing this story. No, I'm not writing it. No way. Not never.
On the other hand...
I've always wanted to do NaNoWriMo, but November is never going to work for me; it's too busy at work, starting to get dark and gloomy and my brain is beginning to shut down for the winter. But I did think it might be fun sometime to write something fast, just have fun -- like I did when I was a teenager -- and let the quality go hang. So this fan fiction thing might just be my challenge for May, my PerNoWriMo (Personal Novel Writing Month). We will see.