@topical_island I see what you're saying, and I really like Sun Titan for a lot of the reasons you mention. But what surprises me is that a turn 1-2 Oath into Inferno is enough to seal up the game most of the time. It must be the fact that it kills in two attacks if there's nothing in the way, but does substantial crowd control if there are opposing critters on the board.
@fsecco That did help. Knowing that the Jace needs to be held in their hand in order for it to be an answer to Inferno Titan is a good piece of information.
You're both right about why Griselbrand and Emrakul probably shouldn't be the only plan, and I agree with you. Maybe I'm just spoiled by how completely these guys can warp the game with one activation or one attack (when things are going well), but Inferno is going to take some getting used to for me. The one other thing I'll say about him is that you don't have to play Tundras, which is nice.