Mad Maggie is fun
I mean, nothing like the last hours of a season to post about its character, but I avoided this character mostly because she was hard to use and I wasted a lot of time playing Diamond games. She's harder to use but I've found her to be one of the more entertaining kits.
Don't know about New Castle, but I think if Respawn stays creative with kits like MM, they'll potentially avoid character glut. Whereas Defense characters are trashed by Respawn, and all move fast characters, obviously over picked and biased, are ruling the meta right now, a kit like Mad Maggie isn't either ruining a prior character, or in a class that makes her particularly suck or be over picked. Aside from the first few weeks of the season, of course.
Fuse is probably another character like this but ever since he got buffed he's on the better side of things. Regardless, his is a kit that could be adjusted always, whereas Respawn has completely kicked Wattson and Crypto in the face, and I don't see them ever figuring out how to fix those characters. I don't think NC is such an amazing concept except his drag away ability, but he's the opposite of MM where he looks like he'll either make other characters like LL useless with his abilities or he himself will be too weak. It'll be far more difficult to keep him in balance range without trashing other characters.
Wrecking Ball, I love that thing.