[whsie]

Originally Posted by Richocet

Spoiler for hmm...:

I can see why Miyuki would be so upset. Feeling the pain of your arms being blown off or being burnt or the stuff is a lot for a human mind to take. She doesn't want her Onii-sama to feel that pain.
When you said the council, you meant the student council right? That means that ability of his is now leaked to them

Spoiler for answer:

Only partially though. When his superior, Kazame, and the others came in the VIP room, everybody in the room was nervous. The major walked toward and then stopped in front of Tatsuya who was acting all nervous. The major addressed him as "captain". Then Fubiyashi (not sure with the name) said that information control was "released". Immediately, Tatsuya straightened up into a military posture and replaced his nervous face with a serious, stern look. Everyone in the VIP room but Miyuki was shocked.

At this point, the others only know of his military background, but not his abilities. They only understand Divine Left after Miyuki explains it when Tatsuya used it on one of his classmates who was fatally injured. Miyuki didn't explain the far more destructive Demon Right and she certainly didn't talk about Material Burst.