This article's content is accurate to the most recent public game version, 0.4.8d.
"Sheds your skin like a snake to recover half of your HP. Also cures poison and removes stat debuffs."
Cost: 50 TP
Source: Equipping the Serpentine Core.
Skin-Shedding Rejuvenation is a skill that restores half the user's Max HP, and removes 
Poisoned and all STAT Down status effects on them.
This is possibly the most potent single target recovery skill available to the player, but it comes with a prohibitively high TP cost that makes it impractical in most circumstances. The most reliable way to be able to use it is with Eric(a) after using Mana Burst.