In many ways Thad looked like Thawne and occasionally acted like him, but what you witnessed with your own eyes right now showed the obvious resemblance. The twisted traits Eobard passed down to his son. The excessive sadistic treatment of someone he loathed, and saw as a threat. Payback that consisted of merciless treatment and a huge grin while the victim begged him to stop. The sadistic choice thad made himself.
How Thad enjoyed himself and the screams was horrifying. His amusement as he decided upon a unique form of punishment.
The fight was over already but that wasn't enough for him. He wanted to leave a internal, destructive irreversible impact on the poor human. He didn't care if the one slipped into shock or if the internal damage even meant he would survive. All he wanted to was put him through the pain.
Phasing his hands through the man's skin and tissue to reach the bone. Then snapping them with his bear hands. Surgical precision followed by agonizing screams and the speedster's chuckling... Then making it even worse by vibrating his hands to shatter the bones while his fingertips acted like knives. Attacking the longest nerves in the body before finally and roughly shoving him with his foot.
He didn't care about witnesses, it wasn't even about watching the man die with the high chance of internal bleeding or damage. He wanted him to live with it, for other people to learn about it.
However all the joy on Thad's face ended when he saw the disgust and horror on yours. When you almost couldn't see a difference between Thad and his father. Between him and a monster and an excuse.