Right now I’m at 80 /color, 80 multi (no more than 2 colors, thinking of adding in a couple triple or more cost), 65 artifact (probably going up to 70 once I get the rest of the foil fetches) and 65 artifact.

Did you consider basilisk collar? I really like that card as it’s fairly cheap and powerful and as we’ve seen recently goes well with red pingers and essentially makes guys unblockable. Not sure if it’s any better than bonesplitter or wargear, but more nighthawks can never be bad.

I like all the additions though. I am definitely going to consider Lignify for my cube.

cards that you might have missed:
*Kor Skyfisher: reuses your etb creatures and works well with knight of the white Orchid / Land Tax / Moxen
*Journey to Nowhere: this card does everything Arest does for 1 less mana.
*Kor Sanctifiers: a 241 disenchant that can easier be reused (might come in for Return To Dust)

*Serendib Efreet: great creature for 3 mana, I need to get one of these soon.
*Rite of Replication: It is worse than clone most of the time (can fizzle, can’t copy shroud creatures, bad with bounce), but it is just so awesome when you manage to play it with kicker.
*Sphinx of Lost Truths: rather bulky for a looter and if you have the mana to kick it, you would be better of with a “real” finisher like Sphinx of Jwar Isle, which has been amazing so far.
*Into the Roil: it is an easier to cast Boomerang early and a cheaper version of Repeal later. A really good bounce spell for this format.
*Mark of Eviction: Yes, this card was good in Ravnika limited, but in the cube you have just a lot more removal which can turn this into card disadvantage for you, if you try to abuse one of your own etb creatures. If you want to play it on your opponents creatures, you have the problem, that he/she can still attack 1 more time with the enchanted creature + you don’t want to trade with that creature in combat, because you would lose your enchantment.

*Sorin Markov: A very good planeswalker with a kickass artwork
*Ob Nixilis, the Fallen: a very cubeworthy card, just keep in mind, that your average cmc for black creatures is already close to 4
Vampire Nighthawk: best uncommon of the set.
*Bloodghast: has like a million applications
*Vendetta: This is NOT a black S2P: you don’t exile the card and it only hits nonblack creatures. Also it is a lot more problematic to pay 5 life than to give you opponent that much, because there isn’t that much lifegain in black, but a bunch of good cards that let you lose life. If you need more spot removal in black: why don’t you have Terror or Doom Blade in your cube? If it is important that your removal costs 1 mana, I would try Disfigure, which takes down most of the small creatures and can act as a combat trick to kill a bigger one.

*Burst Lightning: The lategame bonus makes this Shock very playable.
*Goblin Guide: One of the best red aggro creatures ever printed.
*Goblin Ruinblaster: I would rank it below Avalanche Riders and Ravenous Baboons, because it desn’t work with Blink effects and costs double red, but the gobo is still very playable if you want a third creature with this ability.
*Obsidian Fireheart: yeah, red usually doesn’t get 4/4′s for 4 mana and the flavortext is cool, but thats about it. It is hard to cast + the ability is expensive and most of the time it is just a vanilla. I would highly recommend exchanging this with Plated Geopede. A 3/3 first strike for 2 mana is just as hard to deal with + first strike is even better in red, because the color has access to burn.
*Hellkite Charger: Rorix does more damage, but it doesn’t hurt to have an easier to cast version in your cube. I bet that the hasty dragon will deal more damage than Akroma2.

*Lotus Cobra: Since you mention how awesome these cards + fetchlands will be: how about reducing the size of your cube a bit? With the current number of cards it is just like playing 6 fetches in a 360 card cube. (Not to mentiion that you are going to draw all the other REALLY crazy cards less often).
*Rampaging Baloths: Your cube is a bit slower, so it is probably ok, but I ended up removing it from my list.
*Scute Mob: @Elliot: try to look at it as a 5 mana 5/5 that untaps 4 lands and keeps on growing. I think this is the perfect card for a cube: It is fun to play with, aggressively costed, can be used to satisfy your inner Timmy but still gives your opponent a fair chance to deal with it.
*Wickerbough Elder: I would still play it if it had 1 less power
*Lignify: Hmm, I had Lingnify in my list once and it was just really disappointing for me, but my cube has changed a lot since then. It might get a second chance in the near future.

*Vines of Vastwood is another great Zendikar card that is currently not on your list. Most of the time it is a cheaper version of Stonewood Invocation, with better defensive applications.

*Eldrazi Monument: I doubt that it is that good in the cube, because there are less token producers but more removal available, but it looks good enough to give it at least a try as a Overrun. (Speaking of Overrun: why don’t you just add Overrun and its white version Mirror Entity to your list, since these are the colors that would benefit the most from this artifact.)

*Lord of Extinction -> Nath of the Gilt Leaf: Lord of Extinction was just such a boring card to play with
*Teneb, the Harvester -> Doran, the Siege Tower: the 0/5 loses rapidly in value when you don’t have the right mana to play him early, whereas one can easily splash for a Teneb or just play him in reanimator decks.

Celestial Colonnade / Creeping Tar Pit / Lavaclaw Reaches / Raging Ravine / Stirring Wildwood: I think they will work out well for you, especially the blue ones + your foil set looks very nice

I agree on Obsidian Fireheart being jank, he is. Vendetta hurts too much too often to be a high pick.