The Cure For Envy.

"I pity the kids of this rite of passage." Legion-7 said for the umpteenth time. "You are just like the dragon bullies that participate in the trial of heaven."

That made Legion-5 shrug without guilt. He said, "They have to show me why they are Supreme or they will drown in the shadow of despair."

The young Supreme beasts can surely combine different divine abilities to threaten him so he is not going to underestimate them, but his existence as a giant to be overcome is not disputable. He is the challenge to beat not the other way around. They need to up their game if they don't want to drown in the shadow that he will cast on them. 

He doesn't even need to use the comprehended laws to gain an advantage. He is already ahead of them and his advantage will remain until they become Origin gods. They would have combined all the seeds of power then and truly become Supreme. But until then, his dominance has to be challenged.