Rejuvenation

This mod makes minecraft more difficult by introducing lives, tied to your max health. Everythime you die, you lose one heart of your max health, until you have none left, at which point you will be put into spectator mode."But is there no way to get lives back?", I hear you ask, and indeed there is, and it all revolves around the newly introduced Rejuvenation effect, which can be obtained only by eating an Enchanted Golden Apple.

When you use a Totem of Undying while you have the Rejuvenation effect, you will regain one heart. When you die with your last heart, you obviously cannot regain hearts this way, but you can be resurrected if you also have the Corpse mod installed. Other players can resurrect you by giving your corpse Rejuvenation and a Totem of Undying, and having your corpse struck by lightning*. Since corpses obviously cannot eat Enchanted Golden Apples (or use a Totem of Undying for that matter), other players can give these to your corpse by right-clicking.

*It's recommended to use a mod that either let's you use the Channeling enchantment even when there's no thunderstorm, or provides some other way to reliably create lightning, otherwise you'll be waiting a long long time.

Configuration

The amount of hearts lost on death, regained on rejuvenation, respawned with, and maximum can all be configured. There's also an option to stop a player's last corpse from despawning, so that they can always be resurrected.