Well i'd like to correct something its true that genjutsu mirror ''was'' amazing but as you may know or not now its not that amazing as it was coz it was nerfed.....While before you could reflect all the debuffs now all it takes is one debuff and thats all !! well it could be useful at some case where the ninja causes immediately immobile like in kushimaru or immediate chaos in shisuis case but when u have your water main with its poision tai that catch your ninja in a combo genjutsu mirror is pretty much useless coz everything you''ll get thrown back is 1 poison debuff and nothing more thats why most dont even use that passive while you mentioned its one of best points... I'd say that best point of fire main is the temporary debuff immunity he gives with his mystery and the boost of attack and ninjutsu which most are fire attribute the current meta now in game.