treasure node

TL;DR: How do I beat this level? What silver characters/strategies do I need to use? I don't see how this fight is possible and could use some guidance. We have to use a single silver fighter. Valentine gains a stack of regen every 3 seconds, but she also gains health from her opponent...

How do you do this (specifically talking Master difficulty)? It seems like it requires a specific variant of RF, which is bs, in my opinion. Can’t hit enemies too hard or they gain barrier. Can’t debuff enemies because they get precision and become unblockable. Can’t use variants that self buff...