0:38 is possible if you don't tell AI to attack the boss and only do 2 hits + knockup with Vitis. Galumn kept failing to wipe out remaining HP or the boss kept using the knockback move.

You can manipulate the enemy's initial attack pattern by staying away and letting the boss swing at 00:08 or later. If performed successfully, the boss will summon the balls afterwards.

Vitis - Mithril Garment, Battle Bracelet Galumn - Might Bracelet Juju - Silver Garment, Battle Bracelet, Gold Necklace, Restoration Charm