A Heart of Crystal

v1.0.1: Fixed a bug where, if game rule heartLossUponDeath was false, you'd revert to 10 hearts every time you died, regardless of how many you had at the time of death. If you have 13 hearts, you'll now stay at 13 hearts.

(The 1.21.1 version didn't get this fix as, from my testing, it doesn't have any issue like this in the first place)