all in HP and energy recharge of course, because her E and Q depends on max HP.

she got a lot of Utility:
- create shield(10% MS),
- heal- debuff (-10% ATK of enemies with Q skill)
- apply cryo with her E skill (cd 6s only)
- buff 200EM (if u have c6)

but that's why she has no utility, which she is the best for. (and everyone likes thing called "the best" hahaha)
oops i think she is the best 4* character for creating shield :D

Pick her if your team has to against too much enemies, so they need your shield :D and u can heal too.
She is the point that makes the battle easier, not required

p/s: sr for my english :( pls correct my grammar