>>528486249
For characters with multiple costumes, if you click on that upper right portrait, it'll open a little menu where you can set which bond potential to use.
For Refi, if you select Pure White Blessing, she'll always have hp and def buffed, but if you choose Gluttonous, she'll have HP and mResist buffed.
If you're very new, the values might be 0, but you increase those numbers by upgrading costumes.