Adrian knows that dragons are already very aware of their surroundings as an egg. They will show hostility immediately after hatching if they already felt the bad intentions as an egg. This is also the reason why they can imprint on the people that hatches their eggs as they tend to hatch when they know that the person near them has a dependable personality.
All of the six colored dragons entrusted the life of their sibling to Adrian. Once Adrian agreed, the bodies of the six colored dragons faded into light. All six dragons did not show a face that struggled but a face full of hope.
Adrian thought that the six colored dragons returned to their respective areas, but they actually died. The ones that respawned in their areas are actually colored dragons as well but are brainwashed. All the intelligence that the eyes of the six colored dragons had been gone and no longer present.
Apologies for the late update as I was busy. Please reload as the chapter has been fixed.