life based mjölner, 3rd link in 2.0?

So before the awakening i was using vaal pact with a life leech gem linked to my arc and discharge inside mjölner, and i believe this was the most common setup.
Now with 2.0 we get kingsguard, which heals us 100 hp per endurance charges expended, which conveniently fixes the problem of life leech being nerfed on single targets (atziri). I tested a bit, and for me 3 endurance charges wasnt quite enough to sustain through normal atziri, but i believe 4 or 5 will make it quite smooth.
Regardless, the life leech gem slot in mjölner has been freed up, and so i am wondering, what are you using in your 3rd link?

My first reaction was using lightning penetration. While its a great damage increase, i was thinking that, with the (perhaps?) increased emphasis on endurance charges (larger portion fire damage), maybe empower would actually be better or on par? Might even be worth it to spec out of some lightning damage nodes and into elemental/spell damage nodes on tree?

What do you think? how have you been solving healing in 2.0?