useful to have more than 1 charater know the null spells. haste can help alot as well. just nul spell till you have all 4 elements, attack till he casts a spell, recast that element null, repeat till he summons anima. get yuna to summon aeons, attack with special attacks /overdrives and that should kill anima. then summon shiva to deal with seymore after anima dies. let get get overdrive by boosting her then overkill.