Chapter 73, "Visit To The Elderglow Academy III", is the clearest early answer because it turns Elderglow Academy's situation into a concrete plot event. The setup is Standing in the middle of the teleportation array within a certain..., but the pressure keeps building through This array is connected to the array of the academy and so you'll be....

Chapter 75, "Visit To The Elderglow Academy V", is the clearest early answer because it turns Elderglow Academy's situation into a concrete plot event. The setup is The door pushed open revealing two young boys., but the pressure keeps building through One had slightly long silver hair, blue eyes, and a lean athletic....
Chapter 124, "Academy", is the clearest early answer because it turns Academy's situation into a concrete plot event.
Chapter 504, "beginning (4).", is the clearest early answer because it turns Bandit Academy's situation into a concrete plot event.
Chapter 505, "Consequence", is the clearest early answer because it turns Bandit Academy's situation into a concrete plot event.
Chapter 647, "Collision 1.", is the clearest early answer because it turns Onyx Academy's situation into a concrete plot event.
Chapter 649, "Different Reactions.", is the clearest early answer because it turns Bloodline Academy's situation into a concrete plot event.
Chapter 587, "Shockwave.", is the clearest early answer because it turns Vajra Academy's situation into a concrete plot event.
Chapter 597, "Unharmed 2", is the clearest early answer because it turns Vajra Academy's situation into a concrete plot event.
Chapter 584, "Line Up", is the clearest early answer because it turns Onyx Academy's situation into a concrete plot event.
Chapter 576, "First Day Conclusion.", is the clearest early answer because it turns Holy Grail Academy's situation into a concrete plot event.