Ah...Rider. They're good at missing each other and Berserker still spent time at Ozymandias' home. Still, it's ridiculous they somehow haven't met before now. At the mention of Dorchacht, though, he looks a little bit uncomfortable. That's still a bit of a tender spot that weighed heavily on him. The cost of having emotions and caring is a heavy one.

"It was the least I could do for an ally."

Calling Waver (or anyone) a friend is still something that's difficult for him. Normal human emotions and normal human attachments and relationships are something he's adjusting to. It's such unfamiliar territory for him.

"He would have done the same, or at least what he could have, for me."

This is his way of saying "You're welcome": justifying his actions.