Custom Sword..

[plush thorn]

with vanilla minecraft, you can give health boost while player is holding the sword

for the whole inventory, you need a while loop that detects when the player gets it, and keep looping while the item is in inventory

[icy lion]

^ while player's inventory contains ... would probably work

and then it would stop automatically when they drop it too

you can also set the player's max health if you dont like giving them health boost

[west hawk]

aight

how do I make it like scan inventories