To my knowledge, at the current skill level you would leech 6% life & mana of the magic damage when using Eldritch Blast.
I.e - If your magic damage was 100, you would be leaching 6 health points & 6 mana points.
but thats completyly new, that, when i do magic damage to you, i get leech in return.
it was allways only exclusive for physical damage. physical damage allways did crushing blow.
so, if it does leech now, does it also crushing blow?