I don't particularly like Stalking Stones or Arc-Slogger . If you want a man-land, try Ghitu Encampment , or run Valakut, the Molten Pinnacle s for direct damage.

I really must be missing the point of Arc-Slogger ; it's 5 to cast, has a moderate p/t, but the ability to trade 10 cards for 2 damage is awful, imo. Inferno Titan is 1 more to cast, and is bigger, pumpable, and gets you a bolt each turn. If you want a blocker, AEther Membrane is pretty damn good.

Have you considered any of these cheaper LD spells?:

Raze , Pillage , Tremble

I love Hateflayer in here.

maybe adding a Mirari or two?

I have considered Raze and Tremble , but the fact that you have to sacrifice a land means that my other spells will have to run slower, and it's not a deck where you can fight with little mana. Pillage is a good LD, but it's basically the same as Stone Rain if you are going against someone with no artifacts. Maybe I could sideboard them instead of Demolish .

Arc-Slogger 's ability is more of a clutch. Need 2 damage to end? Need to get rid of that creature that will make your life impossible otherwise and don't have shocks? And if you play it with Rings of Brighthearth and enough mana, you can dish out a lot more.

Mirari ... I'll think about it

If you want to splash black, Destroy the Evidence will up the frustration factor with the deck. Copy it with Chandra and possibly Reverberate along with Dual Casting and your opponent could mill a ton.

I'd put Dual Casting over Arcane Teachings . Bend or Break could be good. I would sideboard Boil and Flashfires for lulz. Lavaball Trap might be good too.