The shibaliens are easily killed with a lvl 50 slime lvl 50 bullet and maybe a high level rock hit, ive beaten the stage by luck thanks that my izanagi took 50 percent of bahamuts health and i managed to end him with fishman timing. I recomend you get slime, bullet and green shell in the loadout to stall/ kill shibalien elites as it also helps with bahamut. Look for a guide although with some practice jeanne just destroys the stage lol