Bring back rdw

ball lightning + assault strobe

However if you are short on mountain mana you could use Arc Runner instead of Ball Lightning

Ball Lightning has trample, which makes it that much better with doublestrike.

Two mutagenic growths plus the combo coukd be a game ender

Two mutagenic growths plus the combo coukd be a game ender

Or one Virulent Swipe. Though the growths have the advantage of Phyrexian mana.

So with a round one swamp followed by a round 2 mountain could be a dark ritual into a heartless summoning with a priest of urabrask into a ball lightning  with 2 mutagenic growths for a round two kill?

Or would ball lightning die before a chance to attack?

Or would ball lightning die before a chance to attack?

No, it would be able attack. That turn two kill would require a perfect hand of seven cards and the draw.  But impressive.

The heartless summoning would kill it before it could be pumped up tho wouldn't it?

What if you added Sundial of the Ifinite then you wouldnt have to sacrifice right?

The heartless summoning would kill it before it could be pumped up tho wouldn't it?

Ack!  Right, I wasn't paying attention there.
And Sundial of the Infinite would only keep it until the end on the next turn, meaning the end of your opponent's turn.

Mountain round 1 with one drop creature
Mountain round 2 sacrifice creature to infernal plunge.  Cast ball lightning with three mana.  assault strobe with other mountain.  Phyrexian mana mutagenic growths times two.  Possible round two 20 damage with trample.

Just needed to work out the kinks a little.  Should all be legal and effective

So with a round one swamp followed by a round 2 mountain could be a dark ritual into a heartless summoning with a priest of urabrask into a ball lightning  with 2 mutagenic growths for a round two kill?

Let's try this:

T1: Mountain
T2: Swamp, Dark Ritual, Priest of Urabrask, Ball Lightening, Virulent Swipe, Mutagenic Growth x 2.

Mountain round 1 with one drop creature
Mountain round 2 sacrifice creature to infernal plunge.  Cast ball lightning with three mana.  assault strobe with other mountain.  Phyrexian mana mutagenic growths times two.  Possible round two 20 damage with trample.

Just needed to work out the kinks a little.  Should all be legal and effective

Sounds like a winner to me.  I have a ball lightning / assault strobe deck as well but I took out the 1/1 goblin with haste for 1 mana to put in hellspark elementals.  I just may incorporate 4 infernal plunge and bring back the goblins who's name eludes me.  I use another neat combo in this deck traitorous plunge and fling, deal double dmg to them and kill their creature in the process. 

That goblin's name is raging goblin he's my favorite