This may seem like a bit much but would 5 phases be good for the final boss (Radagon/Elden Beast)? 2 phases within 1 health bar for Radagon, 2 phases for Elden Beast, and then give Elden Beast a second health bar (3rd phase). Considering the final boss is a god, why not make that a reality? It really needs that buff anyways.
Alternate reality where in his last moments the Greater Will deems him worthy enough as it's protector and candidate for Elden Lord. He actually has an unused voiceline proclaiming himself as King Morgott, Elden Lord
