Loot Context

this

The entity that the loot is generated from.

killer

The entity that indirectly caused death or damage.
For example, if a player kills a mob using a bow, a thrown trident, or an Instant Damage potion, the player is the killer.

direct_killer

The entity that directly caused death or damage.
For example, if a player directly attacks a mob with a sword or trident, the player is direct_killer.

If the mob is killed by an arrow shot from a bow, the arrow is direct_killer.

If the mob is killed by a thrown trident, the trident is direct_killer.

If Instant Damage is applied by a thrown potion, that potion entity is direct_killer.

killer_player

The direct killer is a player.