User blog comment:So-Pro Warrior/Special Sneak Preview of Season 2: Battle of the Ultimate Galaxy Savers: Master Chief vs. Commander Shepard/@comment-26074921-20130614034825/@comment-4541447-20130614045222

Chief has been known to use a Energy Sword as for example such as the duel between him and the Elite Thel 'Lodamee and uses it when he needs to.