The head was the weak spot. That would work. He spotted the electricity flying towards Thor and quickly grappled with him, locking Mjölinr in place and turning him so the bolt hit is back. It barely phased Thor, but it gave Orin time to free his hammer, charge it with electricity and slam it down on the top of his head, where it shattered under the force, electricity sparking through the robot. He quickly caught what was left and said," Robotic Thor is down!" He dropped to the ground, landing with a thwack when he dropped the robot. His hammer charged with electricity and he flung it at Ultron's head, a nearly unstoppable force.