I like this Unique. I think it offers a really interesting, alternative gameplan for Flurry Rogues to solve for healing. This makes Healing Received affixes and Paragon Nodes actually relevant for a build (can you imagine?) - adding much needed variety. The problem is the helm is such a competitive slot…the second you get Heir of Perdition it throws all of this out the window and you’re back to the same build as always.
Heir of Perdition can still be an amazing general option for every build and even for Flurry if you don’t want to deal with any downsides. But if you want to squeeze out that extra 10+% damage…well, you have to deal with your health bar draining, which I think is a new, awesome puzzle to solve.