Bert was quiet for a long bit after that. Those were the powers that the Crimson King's wizard possessed, according to all reports. And Bert believed it, having seen enough evidence in the end times. The powers Alessa was describing were ones he associated with evil wizards and horrors from the Prim.
But Alessa wasn't evil, and she certainly wasn't a Prim beast. And she didn't have those powers now. These weren't tempered by the fact that Bert liked her - he was able to separate his emotions from these sorts of analysis. But she was a servant of the White, same as he was, and she did say she hadn't liked having those powers.
He could understand, at least, not liking abilities that you possessed. He was proud of his skills as a Gunslinger, proud of the fact he could make a clean kill across great distances, proud of the fact he could take out ten men in under a minute before their companions even knew something was wrong. But he couldn't say he particularly enjoyed being a finely tuned killing machine.
Finally, in response, he offered up part of his Gunslinger's creed.
"I do not shoot with my hand, he who shoots with his hand has forgotten the face of his father. I shoot with my mind."