What does Gracewing's ultimate do?

The heal scales off Gracewing's own maximum health rather than the individual health pools of your other team members. Raising Gracewing's health directly increases the flat recovery delivered across the entire party. Because Aniimo of the same species differ in stat distributions, potential ratings, and traits, two Gracewings will produce different raw healing numbers with this ability.

The accompanying boost improves the squad's broader healing capabilities after the initial recovery hits. This fits the combat role of Support Aniimo, who focus on buffing allies and maintaining team stability during encounters.