i love this! it's just simply amazing the character write outs as well they're just so fitting. although i see pinkie pie in personality more as an anti-hero but b/c she is friends with the other mares that would put her in the hero section. either i'm in love with all the girls so far.
Usually, the "loner" in any particular superhero team is a grim, gritty, violent anti-hero who gets his own mini-series where he gets to actually kill people, usually drug dealers. Here the loner is an obnoxiously cheerful trickster who gets horribly depressed if she thinks people don't like her and wants to be friends with everyone.
Ah well. She defeated the Pah Rah Sp'Prait invasion with her sonic abilities, so that's reason enough to keep her around.