1. Use trickster with TP prism or rogue with planewalker
2. enable unsafe prism and teleport to an area that looks black. if it is an unloaded tile, it will reveal and you will be teleported. if it is a black tile, you will be disconnected.
the most obvious use would be jumping rooms in davy's, but i used it in undead lair and ocean trench a while back as well.