Niv Mizzet, Parun looked insane when he was spoiled, and after playing him in Oath in the Inferno Titan slot, I'm in love.
Inferno Titan deals a guaranteed 3 damage when entering the battlefield, but Niv has so many synergies with the rest of the deck that he is almost always much better. Dack, Jace, Sylvan Library, Brainstorm, Ancient Grudge, Repeal, Griselbrand's activated ability---all of these become completely absurd once Niv is in play.
Steve in his podcast expressed concern about the difficulty of assembling six colored mana, but I've not found it to be a significant concern. Sometimes you do have off-color moxen you wish were Islands, or 2 blue sources, 1 red sources, and a Black Lotus---but in the late game I'm almost always happier to have an uncounterable creature for UUURRR than a counterable one for 4RR.
The other liability is that Niv can be bounced by Karakas, whereas the Titan cannot. The notion to replace Mox Pearl with Strip Mine has crossed my mind from time to time.
Here is the list I'm currently testing.
4 Oath of Druids
2 Niv-Mizzet, Parun
1 Griselbrand
2 Dack Fayden
1 Jace, the Mind Sculptor
1 Arlinn Kord
4 Force of Will
3 Flusterstorm
3 Mental Misstep
1 Sylvan Library
1 Ancestral Recall
1 Brainstorm
2 Preordain
1 Time Walk
1 Yawgmoth's Will
1 Demonic Tutor
1 Gush
1 Dig Through Time
1 Repeal
2 Ancient Grudge
1 Memory's Journey
1 Null Rod
1 Black Lotus
1 Mox Emerald
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
4 Forbidden Orchard
3 Misty Rainforest
3 Polluted Delta
2 Tropical Island
3 Volcanic Island
1 Underground Sea
1 Island
1 Library of Alexandria
4 Leyline of the Void
1 Nihil Spellbomb
1 Nature's Claim
1 Pithing Needle
1 Pyroblast
1 Shattering Spree
1 Ancient Grudge
1 Energy Flux
1 Blazing Archon
1 Mindbreak Trap
1 Firespout
1 Sudden Shock
last edited by evouga