Nuclear bomb glitch
From Halopedia, the Halo wiki
Start by performing the Arm glitch with a gravity hammer. One player (Person A) must be in Edit Mode, with the other player (Person B) in Player Mode; both players must attempt to grab a Gravity Hammer at the same time.
At this point, Person A should hold RT and rotate the Gravity Hammer until Person B's arms disappear, at which point B may begin to hover for a moment. Viewing the Film frame-by-frame in Theater reveals what actually happens: first, Person B's character's arms bend and rotate erratically, sometimes passing through their body. Next, the hands expand to huge size. Immediately following that, the surrounding area is engulfed in a massive white light.
At this point, Person A should enter Player Mode, to avoid accidentally deleting the Gravity Hammer.
While all of the above happens, the glitch will inflict massive damage upon any other players in the level; on at least one occasion, it has almost instantly killed a player on the opposite side of the map.
At this point, the glitch has been activated. If the glitched player (Person B) then swings the Gravity Hammer (by pressing RT) right as a grenade is thrown by another player, then Person B will deflect the grenade, while also amplifying its power to such an extent that the explosion briefly engulfs the entire map. The glitch will also cause Person B to be able to run through the air.
Additional phenomena occur when pressing RT. Among other things, Person B can travel through most surfaces; for instance, if they enter the blue room on Snowbound, you can pass right through the glass floor above by pressing RT and then jumping. Finally, if Person B were to abuse the RT button and then switch to their secondary weapon, they would be completely invisible and invincible—others would only see Person B's gamertag or waypoint, and Person B would be invulnerable to nearly everything -- including the turrets on Snowbound and the mines on Sandtrap, but excluding kill barriers and falling to their death.
- Meleeing the glitched player to death will cause the game to lag for the connection host until the glitched body disappears.
- If the glitched player attempts to swing the Gravity Hammer, their body will move as if it were in fact swinging a hammer.
- From the glitched player's point of view, they are still holding a Gravity Hammer; however, nobody else can see it.
- If the glitched player throws a grenade after their arms have been removed, their arms will briefly return while the grenade is thrown.