Maybe. But possession is possession. Although it wasn't to the extent you'd usually see from demons, the shadow still exerted a certain influence on me, so it should count.

Of course, I'm not saying that to avoid responsibility. As you've said, I wasn't exactly in my right mind . . . but it was still my mind in the end. Half the reason I snapped her neck was because I wanted to end it quickly.

[In other words, he wasn't completely gone. He didn't want to make her suffer more than she had to—not that it changes the fact that he killed her in cold blood while she struggled against his hold. Sieghart swallows at the memory.]