A Mythril Second Heart gives you 50% more max HP, however you are unable to heal back or regenerate this additional hp. Once lost, the extra health will be gone for the rest of your current life, and only reset once you die or quit/reload. When the extra health is active, your damage absorption is reduces significantly. When the extra health is gone, you gain +2 life regen.
The Mythril Second Heart is a Hardmodeaccessory dropped by the Mythril Slime in Expert Mode. It gives the player a temporary 50% increase to max health which cannot be regained after it is lost until the player dies or leaves the game. While the player has this extra health they lose 10% damage reduction, after losing it however they gain +2 life regeneration.
Mythril Slime
