A lot of specials are pretty bad. Good ones include: Arrest, Hell, Demon, Charge, and Berserk. Chaos, Spirit and maybe Gush can be useful depending on the class. Also some weapons have unique specials that are useful like Tsumikiri J-Sword. As for evp and def mats. They are mostly not helpful but they can be used for certain classes that have extra materials leftover after maxing atp, ata, luck, and mind. You can leave em in the bank or get rid of them. It doesn't really matter too much. You're probably best off without the joke character lol.