I was highly disappointed that Arella didn't play a larger role in season 4. She was there maybe 3 minutes, and was gone. I think more can be done with Arella, something I intend to do with my Slade/Rae ficcie. AS you can see, the two sketchs are with the child Raven, so she'll be around during The End, I think that's all I'll say.
Arella, Raven, TT (c) DC Comics and Cartoon Network