it worth but it costs usually 300k-500k per char....but it really worth for earth chars...about 70% less dmg pwnz! :D fire only for mages i think...not that much dmg for melees....water is usefull to...wind...hmm dunno :P

edit :

the fight is against 8 level 130 guards with terra, coma, mess etc and really painful dmg :( 3 of them does NOT respawn...the rest of them respawn two or three times i think ....so really hard fight...takes about 30-45min per fight with 2 level 180 fires and reborn water if you dont help...and you should not help if you r "low" level....:D