I was never a fan of too much righteousness like Batman never Killin Enemies, even tho those scums kills off hundreds.
Ofcrs Twice wasn't really a bad person, bt he had also killled in the past and his abilities made him one of the fearsome villain in this battle. It was even mentioned this chapter, Twice by himself would have been enough to take out majority of the Heroes, so it was absolutely necessary for Hawks to take Twice out, for heroes to have any chance of victory.
It's like blaming Hawks for not being completely righteous when the fate of cities or nation depended on it. Hawks didn't have such luxury, and in heart he really wanted to save Twice.
And i say so being fan of Twice, i also liked Hawk this chapter, he stood better than i expected even tho he was short on feathers and Dabi fire is his natural weakness. He is accomplishing something other heroes couldn't do, he had to endure working with the enemies, risking everything so as to make the Heroes stand a chance at a victory. So i dont find the criticism right from other fans here.