Xeno-Dokei plus a companion. If you are sticking to bosses, use Xeno Dokei. The similarity between the Xeno-Dokei C ability and Burning Breath makes Xeno-Dokei a great replacement for Kaijin. That being said, to make up for the loss of the monkey king, you probably should equip another companion to bait out those boss moves. Oh, and make sure that companion is high level so that he does not instantly die to one of the boss’ moves. I’ll mention quickly that the only way to farm companion exp is through green scroll quests.