Fused armor glitch
From Halopedia, the Halo wiki
The Fused Armor Glitch is two very different glitches that happen in Halo 3 and Halo: Reach.
Walkthrough
Halo 3
In Forge mode, put down a turret with a very fast respawn time. Have someone remove that turret from its base. Put another turret down in as close to the same spot as the first one as possible. When the original respawns, they will be overlapping, and one person can man each turret, causing their models to overlap.[citation needed]
Halo: Reach
This glitch occurs when performing a mid-air Assassination with an Energy Sword. When a player performs this glitch, the player's and the other player's armor will seem to fuse together. There are countless combination's which make large amount of results.[1]
Sources