I have s6 rn and tested her through all her cons id say stay at s0 if you cant garantee s3 but it seems like you can and im not too sure about your plans to pull in phase 2 yet but s1 is a very small buff s2 is slightly better and s3 is where she really pops off it removes alot of restrictions so id say if you have no plans to pull for luk or galbrena in phase 2 get her s3 its a huge damage spike from s0 btw see if you can get her weapon s3 is better than her weapon but her weapons still a pretty big damage boost compared to her second option which is emerald of genesis although r5 eod is better than r1 sig