And if you'd like an idea of some (but by no means all) of the characters who aren't there but should be, some Fandom High wishlists:
1 | 2 | 3 | 4. Yes, some of those are from last term - most of them are still applicable!
Also, potential characters can (but aren't required to) be tried out in a no-strings, never-happened FH setting at fh_launchpad.
ETA: And not an admin, but happy to answer questions like "Does this game eat your brain?" (yes) and "Did Hamlet, Prince of Denmark really set off a volcano at Prom?" (also yes) and "What's with all the glitter?" (It attracts boykissy).