No matter if the black shadow and the red silhouette join hands or if there are other supervisors involved in this sudden change, Aster can tell that the blue flaming board won't let them interfere directly like this again, which is why they pulled out all the stops in a try to trample them.
As to how he knows that the blue flaming board is way stronger than them, that's simple, if that wasn't the case, the last test would have started before they could even have a rest, which means that even doing their best, those guys still had to obediently respect the bottom line of the blue flaming board.
What's more, they got properly rewarded so no one is able to pressure the blue flaming board into going against its integrity when it comes to punishments and rewards, which is a good thing.
