I'd probably rank the characters like so:
S
Joker: Duh
A
Ryuji: Amazing, consistent physical offense and superb durability. Good support in the form of Matarukaja. Gets Charge endgame.
Ann: Solid magical offense and status utility. Tarunda is extremely useful for bosses. Gets Concentrate endgame.
B
Makoto: Solid magical offense, great general utility and an amazing statline (her HP and SP are both high for some reason). The go-to support character by endgame.
Yusuke: Great physical offense, Rising Slash is amazingly clutch (though ineffective against bosses), Masukukaja is actually great in this game.
Morgana: Solid magic offense and good support. Early access to Mediarama is awesome and he has Lucky/Miracle Punch, giving him significantly more utility against minibosses than most casters.
Haru: Her gun skills are amazing and she has solid support skills, but she joins late.
C
Hmm
S
Joker: Duh
A
Ryuji: Amazing, consistent physical offense and superb durability. Good support in the form of Matarukaja. Gets Charge endgame.
Ann: Solid magical offense and status utility. Tarunda is extremely useful for bosses. Gets Concentrate endgame.
B
Makoto: Solid magical offense, great general utility and an amazing statline (her HP and SP are both high for some reason). The go-to support character by endgame.
Yusuke: Great physical offense, Rising Slash is amazingly clutch (though ineffective against bosses), Masukukaja is actually great in this game.
Morgana: Solid magic offense and good support. Early access to Mediarama is awesome and he has Lucky/Miracle Punch, giving him significantly more utility against minibosses than most casters.
Haru: Her gun skills are amazing and she has solid support skills, but she joins late.
C
Hmm