Hologram Glitch

Somewhere in the level out in the open in front of the sniper base there is a flaming pillar. Go to it and get a wraith. Some people report that slowly pushing someone into that pillar will push them through and they will get killed by the gardians and other say that boosting them with a wraith works also. The idea is that you can force someone into the pillar and they when they are killed by the guardians they will spawn on top of the level. The effect is especially cool when you have a sword.