Twenty-One isn't out yet (I'm making a short story) but I didn't want to keep you waiting for too long. Here's a short little generator:

Clan of Your Favorite Leader—Prefix
ThunderClan- Wink
WindClan- Blink
ShadowClan- Mink
RiverClan- Ink
SkyClan- Skink
Tribe- Shrink
Can't choose a favorite- Pink
Other- Rink

Clan of Your Favorite Villain— Suffix
ThunderClan- tail
WindClan- sail
ShadowClan- flail
RiverClan- trail
SkyClan- gale
Rogue- hail
Can't choose- pale
Other- veil

I'm Winktrail! (Bramblestar/Firestar/Squirrelstar and Hawkfrost) What about you?
And uh sorry if it doesn't make sense, it's hard finding things to rhyme that would kind of make sense. And rhyming in general is not my favorite. So if you got like Rinkpale or something sorry.