Friendship? Fuck that... it was the Apocalypse.
Nobody gave a damn about what friendship entailed in this new world, and neither did Simon.
Sure, there was a faint twinge of guilt for betraying her trust like that, but it was quickly snuffed out by the prospect of survival, power, and everything that came with it.
It had already been proven time and time again: kindness was a weakness. Even if he tried to be understanding, even if he tried to build bridges, there would always be people who wouldn't hesitate to stab him in the back the moment it suited them.
If people like that thrived in this world, why the hell should he be kind?
Besides, raiding Adrian's base promised too many benefits to ignore. The operation was risky, sure, but the rewards — oh, the rewards — were worth it. If he could eliminate everyone who sought refuge there, he'd jump through the rankings like wildfire.