this is a great edgeguard against characters like DK who have up b's that are hard to punish with anything good. basically, leave a dsmash mine around the ledge, and wait till DK up b's. when he passes you vertically, hit L or R to roll onto the stage which does detonate the mine, but doesn't hurt you at all. the mine will push DK upwards which is right where you want him, along with doing a good amount of damage. try it out.