Alright i'm back to thinking that Kris is the one who knocked out Susie and dusts Ralsei.
Only because in the dialogue afterwards, Ralsei goes out of his way to utilise lowercased "you" the entire conversation, except for the one line where he says "You were so brave" followed up by starting a new line and confirming it's only beginning, "isn't that right, Kris?"
So i'm thinking that in the "secret" relationship Ralsei and Kris have, Ralsei might just be being forced to along with the plan.