Refinements:

Obtain the "Wax and Wane" effect after an Elemental Reaction is triggered, gaining 24 Elemental Mastery while losing 5% ATK. For every 0.3s, 1 stack of Wax and Wane can be gained. Max 5 stacks. For every 6s that go by without an Elemental Reaction being triggered, 1 stack will be lost. This effect can be triggered even when the character is off-field.