Victor was somewhat reluctant to get into the ring with Corey, but his fight was up, and he couldn't come up with any excuse to avoid what is coming.
It's not that he feared facing Corey, but what happened to Samantha shook him up. Based on Samantha's confidence, Victor expected that Samantha will crush Merve. He also considered the possibility that Samantha was just boasting and that she will end up being slapped again. What he didn't consider was the possibility of her being brutally beaten, and it was obvious that Merve denied Samantha the possibility to give up.
Suddenly, that useless adopted peasant girl was not so useless anymore. And she was scary. Victor was confident that no one from the current audience will dare to label Merve as a peasant going forward.