BangOO's tragic past >>> Pluton
I've actually used this concept before watching One Piece, it's fun. Not sure I'll still use it, but in the past I had an attacked called: "Hellpain Harpoon."
The gist was you formed a harpoon out of magic, tethered it to yourself, then damaged yourself with it as much as you could. Then, you threw it at your enemy, and they felt your pain, on top of whatever pain the attack inflicted onto them as well. It also caused you to feel all the pain you had ever inflicted.
Long story the main character was born to a crazy genocidal alien queen, who brainwashed him to be unable to feel love, and used him to wage war against Heaven for millions of years. Eventually, he broke the brainwashing, and became a good guy, but only after murdering billions of Angels and other beings in magical combat.
He used Hellpain Harpoon against God at one point, so it was the reincarnation of a genocidal alien prince's pain getting added on top of all the suffering God had "allowed" as the ruler of Gaia/Earth.
Neither had a fun time, lots of screaming. LOTS OF SCREAMING.
Kuma and Zoro is still the best "transfer of pain" scene I've seen in anime, though.