my method was to just yunas special dress sphere. it was remarkably easy, but then my party was high 4 chapter 3.

just wait till the magus sisters! they have a zanmoto equilvent move(delta attack), and then all 3 get a turn(unless u r quite fast) as opposed to just a dog.not exactly fair. alsothe first compulsory boss that is DEFINITLY harder then the last boss.