Forged in Blood

Warning: This mod is intended for multiplayer. If you're in singleplayer you can get locked out of your world permanently.

Forged In Blood adds a new block, the Altar, a life system, and a sacrificial knife. 

Every time you die, you'll see the heart in the bottom right of your screen decay. Once you've died 3 times, you'll be locked into spectator mode.

If someone stabs themself with a sacrifical knife, they lose a life but gain the "Bleeding" effect. This can be used to start a ritual at the altar.

If a player who lost all their lives flies over to an active ritual, it will be consumed and they will revive.