https://e621.net/post/show/395838

It needs something like, character:Felicia_(darkstalkers)_(cosplay) but I'm not sure if that's the correct way to do it.

Arrow189 said:
It needs something like, character:Felicia_(darkstalkers)_(cosplay)

"felicia_(darkstalkers) cosplay"

hslugs said:
"felicia_(darkstalkers) cosplay"

This tag would contain both the character cosplaying as others, and others cosplaying as the character. I'm seeing in the other thread it's what's expected though.