STARSHIP HALO TROOPERS: Halo X Male Starship Trooper Reader

(Halo 5 guardians, halo reach, and red vs blue x male starship trooper reader) what happens when the unsc, and convent fight against a new enemy species with the help of another space military though they never heard of them but that all changes when enemy species attacks an crashed UNSC frigate and a covenant carrier.