Affliction Warlock of the Mists' Back Mass question

Hi,

Does anyone know how do the Warlock of the Mists' Black Mass Affliction skill function? (not sure did I miss the information anywhere.)

Like what is the rate minions are taking damage from the affliction? how much life regen are we getting from the minion's life degen?

When the minion explode when reach 1/5 of hp , how much damage are they doing? and what is the radius of the explosion? (just want to compare this with the traditional minion instability.)

Bumping this as I am also interested in the numbers for the explosion.