"Any card—so long as it exists—has a power that is needed."

“These aren’t voices of rage… They’re afraid–of Ray… That’s why they were hoping to stop Ray… Don’t be afraid! You don’t have to become the Supreme Dragon King to be strong! I’m going to prove it to you!“

So, basically, just as Yuya was afraid of becoming the evil Z-ARC, the Dragons were worried about their own survival, too.  Also the underlayered “cries” under their roars was a neat touch, though I could’ve sworn it was part of a bgm here