To me it seems like he has decided. I do not know what his decision is -kill Arachne or turn around and kill Mah'ri- but he is definitely getting reconciled to loosing something important.
He's crying. o_o Arachne never did anything nice for him that I can recall, Mahr'i is giving him everything he ever wanted, and he - is - crying. What the Abyss?
Well, we do not always choose who is our friend or who we fall for. Common sense and emotions do not always go hand in hand. If Arachne is a friend of his, being ordered to take her head is not going to be easy.
By the way, this is a brand new side of Wolf, isn't it?