This final checkpoint of the final boss probably took me over an hour. I almost beat the boss ONCE without knowing what the Soul stone did, which means I probably almost beat it without healing. This was a one time thing and most of the time I was very far off from killing him. I looked up a video and then understood how to use the Soul Stone. You can use it in small bursts with LB which will give you some health back or wait and use it when the bar is at 50 percent for a Soul Storm which will revive a downed character with a sliver of health and allow you to get some health back whiles it active, I believe. Hit both bumpers at the same time when your bar is at 50 percent to use Soul Storm. Using these soul bursts also charges up your meter for your power attacks which are good to use when available. Aside from that its alot of blocking for most of the attacks and most of the patterns are pretty simple but the fight goes on for 7 minutes. It was close but much easier once I knew how to use the stone.