Mephisto couldn't help taking a step back after he said this before revealing an embarrassed look.
It was the embarrassment that came from having been forced back a step like this by someone he considered a lowly human. It was a blow to his pride as a powerful Demon Count for something like this to happen.
So he couldn't hold back his anger that came after the embarrassment as he suddenly raised his tail and whipped it out at the fourth prince's men in front of him.
They were far enough that they weren't hit directly by the tail whipping at them, but the shockwave that came from this tail whipping out was enough to force them all back. If they hadn't braced themselves before it happened, then they might have even been picked up off the ground and tossed away.
That was in a situation where they were wearing full armour, so they weighed far more than usual.
That was more than enough to show how much power was in that tail whip.
