Is there a way to make an ally (character) character who follows the player and fires to a specific character without using the behavior tree?

Yes, this is in 100% possible as I know, means you can use all engine functions available in Behavior Tree But question is - why not Behavior Tree? If you have very simple ai, you can do it in it’s blueprint but doing it with Behavior Tree is much better and easier, just start with Behavior Tree an…