Edge's spear to The Undertaker is arguably the most famous example of this taking place in a real life WWE ring, such is its rarity. More often than not, it will be a suplex that sends your opponent through the wall of the cell, which would be low down on a list of possible moves to do this with. All you need to do, with one finisher stored, is stand your opponent up in a corner of the cell. The OMG icon should appear when you're facing your adversary and a tap of the finisher button will send them flying through the cell wall.
