>>44313295People dying I guess. Based on the fact that any of the students can easily join the professor, I'd argue that had Edelgard presented it properly all of the monastery aside from Flayn and Seteth, would have joined her without a fight.
That's something that they really should have done with the DLC, make it so if you take the right choices in your path you can recruit everyone by the end, even the house leaders and vassals, but it would have to be really hard. Like, you can't recruit any of them pre-timeskip, none of them can die in battle and it has to be in maddening mode, and you have to recruit them all after battle in part 2.
