So for what it's worth I think renewal fits what we want for team sustain pretty well but doesn't result in as strong an effect for Resist, since intrinsically it makes our arts better at recovering from damage than mitigating it in the first place. Against an opponent like Cai with dispels that don't just disable arts but also make recasting harder/impossible, that's less than ideal. Plus, a lot of our effects really benefit from not getting interrupted even for a little; just not healthy to present opponent that window of escape.
To that end, while I'm fine with keeping Renewal as a keyword for the sustain portion of the art, I think we'd be better served with something like [Void, Ocean, Eternity] and other indomitably-themed keywords; an intrinsic weight to arts making disruption a fool's errant. Alternatively, something like [Consumption, Inevitability] to actively devour and get empowered by attempts to disrupt our arts, possibly directing the energy into extra regen or buffs to the supported arts.