Make an NPC follow and attack you through the whole level?

hi guys, I am making a police game and I need the final level to be done but I am so confused since I am pretty new to this. I need to make an npc follow the main character and shoot bullets at the main character the whole time. So how to I make the NPC follow and attack? my character uses the 8 direction tool just to give some background info

Here is an example of a simple follower for 8-direction

howtoconstructdemos.com/simple-follower-for-8-direction-behavior-capx