Krogan Battlemaster (enemy)

"Surrender. Or don't. That'd be more fun."
The krogan battlemaster is a krogan that was sent to Therum by Saren Arterius to extract Liara T'Soni and bring her back to him.

Overview
After releasing Liara from the Prothean bubble, Shepard and the crew take her on the elevator. Unfortunately for Shepard, the krogan battlemaster and a small squad of geth are waiting for them at the top of the elevator. The battlemaster explains that "Saren wants her and Saren always gets what he wants." Seeing no way out of the situation, Shepard engages the battlemaster and kills him before escaping the destroyed Prothean ruins of Therum.

Tactics
The krogan battlemaster has high shields, immunity, and the ability to regenerate health. He uses biotics to disable you and will charge at you if you get too close. The best thing to do is to keep your distance and slow him down using biotics. Once you have him where you want him, open fire. Keep in mind that if you take your time, he will regenerate his health, resulting in a longer fight.