One on one Enemy AI in mecanim Unity 4.6.2

I have been struggling with enemy AI for a very long time and have asked two questions before this one. I have finally understood that making a proper skyrim style A.I is pretty hard so how can I make one like in the video here?

https://www.youtube.com/watch?v=I2gsZPjDNMQ

Also, here is a sneak peek of the game I wish to make:

https://youtu.be/0ouP2TYj7FM

Thanking You,

Shubham P.

Thank you for all your comments. I figured it out myself