Rejuvenation

Under Rejuvenation, dying takes one heart of maximum health, which makes the game harder. A player who loses the last heart is put into spectator mode, and the way back is the Rejuvenation effect. That effect can only be obtained by eating an Enchanted Golden Apple, and the Totem of Undying can also give Rejuvenation, which regains one heart per use. A player who dies with the last heart cannot regain hearts directly, so the mod provides the Corpse mod as an optional dependency and lets other players resurrect a corpse.

Rejuvenation is built for survival play on servers, where a server owner decides how hard the rule set should be. Other players can resurrect a corpse by giving it a Rejuvenation Totem of Undying, and a corpse can be struck by lightning to start that process. The author recommends the Channeling enchantment for reliable lightning, because a thunderstorm alone is unreliable. A configuration option sets how many hearts a respawning player receives, and another keeps the last corpse from despawning so it can always be resurrected.

Rejuvenation requires NeoForge, is published for 1.21.1 only, and the server must run it while players may leave it out. The mod is open source under the MIT License. Corpse is optional, and a version of Corpse must be installed to enable corpse resurrection.