SMP Concept-
every player joins with a Tier 5 Crown when they join the server for the first time. Which can be upgraded using recipes(You have to use a plugin for recipes or code recipes yourself)

Tier 5 crown gives permanent resistance(+4 hearts)
Tier 4 crown gives permanent resistance and speed 2(+8 hearts)
Tier 3 crown gives permanent resistance, speed 2 and fire res(+12 hearts)
Tier 2 crown gives permanent resistance, speed 2, fire res and strength 2(+16 hearts)
Tier 1 crown gives permanent resistance, speed 2, fire res, strength 2 and regeneration(+20 hearts)

If a player dies(Naturally or gets killed), his crown tier resets to Tier 5

Note-This is a multiplayer datapack so if you want to use it on a server, use PaperMC and use Custom crafting plugin and set recipes for upgrading crown



/function crown:give_crown Tier 5 crown

/function crown:give_crown4 Tier 4 crown
/function crown:give_crown3 Tier 3 crown
/function crown:give_crown2 Tier 2 crown
/function crown:give_crown1 Tier 1 crown