It's as if that reminds him of what is actually happening - he's not just talking to his ex-lover, he's talking to an enemy. As she extends a pleading hand, he meets it by lashing out with his staff, the end shifting to the shape of a spear as he presses it close.

"I should kill you," he hisses. It could sound like a threat, but it's more like he's stating a fact. Like he's trying to keep himself together.