I’d love to see a mirror in Halo for a number of reasons.
1 You can looks at your self, not very usefully but would be the first thing you’d do !
2 If you fool an enemy by standing in the view and let him waste his ammo on a wall
3 Could be used as a advantage and disadvantage for camper.
If it could switch to plain glass it would make one wacky “Hall of mirrors” map and make long range weapons almost useless