It's an SK ability. It's not what it once was. It works like this: get your epic 2.0. It has the ability to lifetap for 50% of your melee damage for 800 hits. Pull a train. Turn around and click your epic. Hit Visage of Death and your defensive Spire ability. Mobs must be light blue at least in order for this to work otherwise mortal coil does not proc. The amount of ripostes on a train will be enough to keep you alive due to the melee lifetaps. Mortal Coil is a proc ability AA that will basically do the same thing as your epic 2.0. When mortal coil procs you have 2.75 minutes or so to get it to proc again. Keep pulling trains. Keep pro'ing coil. If you can't get coil to proc - go back to your epic or use Leechcurse Discipline.
Its a technique employed by SKs in the past to kill large quantities of mobs in a short time. It won't ever effect you at this point.
