"They never do." She shakes her head, turning back to Eclipso. "Do you honestly think everyone secretly wants to be sitting on a throne of skull--eh, stupid question, you probably do." As Shepard realizes she's giving Eclipso too much credit, her eyes start to glow with the blue-white of a powered-up biotic. "Let's find out just how immortal you really are."

Shepard has deep and unshakable principles, but none of them involve anything that might reasonably be described as pacifist.