How do I look for which object has the instance variable equal to the global variable?

I'm creating a super simple mmo and I wanted it to have four varieties of enemies, and when I hit the enemy he gets angry and then attacks me nonstop, but there are five enemies in the level each level with a variety of enemies. I need that when hitting it saves which of the five was hit and what was hit, but if I do it without variable it only attacks me once but if I put variable I want it to make it angry only the enemy that has the variable of which of the five equals the variable that saves when hitting.

If you hit the enemy then you set the instance variable on that enemy, should be that simple? If for some reason you must save what was hit then you can save the object UID as a global variable.