Shadowslash knew that he had to control his anger so he had to test their strength first before deciding on how many he will face at the same time.
He looks at the leading Behemoth and says "You will be the first one, you can start whenever you want."
The leading one was stunned, he pointed at himself, seeing the affirmation in Shadowslash's expression, he became depressed.
No one wanted to be first because they wanted to see his combat strength first before initiating their challenge, they only look excited and raring to go because they don't want to be seen as cowards.
He could only curse his luck and steps forward, Shadowslash was uninterested, after being baptized by the killing intent, his spirit has gone stronger.
He had also modified his current body, it might not be as perverted as his true body but it is still considered as terrifying compared to most beings of this plane.