When mob attacked by player procedure trigger?

I wanted to make an armor that, when fullset, makes every mob you attack on fire. But when I tried to make the procedues, when I put the armor on, every entity that is damaged in the world goes on fire...I want the effect to be applied only when player Attacks another entity, i would need some help, and maybe a custom code idk.

And another thing: can this be specified when player MELEE attacks? Because this procedure would ignite fire on any entity hit by any weapon, including bows or modded guns. How can this work with melee?