Thanks for the chapters!
Juumonji is an idiot. Just overwhelmed his opponents himself in a flashy manner to demonstrate how powerful the ten clans are and then suggests Tatsuya joins them. What is he thinking? If the ten clans could see Tatsuya as an equal or valuable member he wouldn't be so ostracized and shunned by the main family. While Tatsuya is an exceptional fighter and CAD technician his inability to use general magic quickly or strongly will mean he'd be looked down on by the clans while monopolizing his abilities and minimal acceptance. Otherwise Saegusa and Juumonji wouldn't have been ordered by their fathers to make an overwhelming victory in a flashy manner to play down Tatsuya's achievement of beating a member of the ten families.
@Zael It hasn't been ended, it's just continuing under the title Mahouka Koukou no Rettousei - Natsuyasumi-hen.