I'm trying to do this quest, but it seems impossible. Item level 198

It doesn't matter how fast I cleanse these NPCs. I run in circles spamming Esuna. I use the Fairy's AOE Cleanse. I try and heal.

But the NPCs will jump up from zero stacks to 3 in a single hit (5 stacks and I fail). They will lose about 30% of their health in an instant and my strongest heal restores about 2% of their health (if any die, I fail).

I am almost ready to give up. I have watched a guide and followed it, but this just seems like something that would be difficult if I were allowed to be level 70!