If you use Thrill + Bloodwhetting then use Shake it off, there's a glitch that can trigger that causes Shake it off to heal for several million HP. You also have to be playing solo or everyone in your party must be dead so you're the only one hit by Shake.

It's an inconsistent glitch with basically zero application due to it only affecting the direct heal & not the regen, but also by virtue of it being inconsistent to pull off since it can heal for the base amount, potentially zero, or several hundred thousand to several million. Then on top of that it only works when you're the only one hit, making it have zero application to group content. That being said, I wouldn't advise playing with it since Ungarmax already showed Square can start slapping timeouts & bans to people who even try it out after the fact, which is likely what the Balance is trying to protect people from.

So play around at your own risk.