YEs, Luna was the dominant of the two. So now I guess Kylo is stepping it up? Makes perfect sense to me. Further evidence:

Kylo has not killed a single mouse... Luna's tally was 3. I had never seen Kylo 'on the hunt'.... UNTIL... last night. In our kitchen at the pantry door I saw Kylo crouched in the 'spring into action' pose. I have never seen him do that until last night. Nope, I didn't see a mouse, and he didn't catch one.... but I think he has taken up Luna's place as protector of the castle. - JamesJM