meeeeeh...
i'm lazy to write description. Maybe later that will change...

ok, in short, that datapack change a death mechanic. Hardcore or survival? It's middle of them.
You have 13 lives. And then > you doesn't respawn
( You can remove datapack or use "/datapack disable ad" for change Gamemode )

What about totems? Every die remove 1 Max HP
used 1 totem? > your max hp 19
used 2 totems? > your max hp 18
...
used 19 totems? > your max hp 1
used 20 totems? > you die. > your lives -1

every die Totem Score is update to 0