Maybe add Selvala, Heart of the Wilds, double Omanath's power each turn.

I'll definitely keep that in mind. Hadn't thought of that before.

Vedalken Orrery so you can cast anything at instant speed, including omnath if he gets removed to save your mana reserves

I had an Orrery in the deck at one point, but I cut it. I didn't find myself casting spells at instant speed, and I don't generally like leaving mana floating when it's not my turn. I find that if I do, it just incentivizes people to kill him and deny me of the mana. In addition, I really only cast Omnath to kill him and draw a bunch of cards.

Helix Pinnacle

I was playing Helix Pinnacle for a time, but I ended up cutting it. It had to stay on the board for a whole turn cycle before I could win, where Squall Line or Walking Ballista can end the game as soon as they're cast.

How about Snow-Covered Forests and Extraplanar Lens for some more big mana? Also Early Harvest

I've certainly thought about Early Harvest. I might put it in the deck, but the cuts are going to be a little tough.

I had Extraplanar Lens in with just regular Forests for a time, but I cut it. There were times where I would play it and pass the turn, to have it blown up. I may reconsider it at some point, but for now I'm good.

For the basics, I already have a bunch of foil Forests, and I don't really feel like getting that little bit of extra benefit from having Snow basics.

If you decide to go back to the lens, I would suggest getting the snow forests so it only helps you instead of anyone with forests.

Been going over this list a lot lately, so I'm just gonna write down my thoughts here for posterity.

Squallmonger is a nice redundancy for Squall Line that can be found off of Worldly Tutor and Chord of Calling; it's a bit more expensive for non-infinite kills but I think it has some nice extra utility.

More interaction in the form of Natural State and Nature's Claim is always something to consider, depending on how many stax pieces you generally face down.

Soul's Majesty and Garruk, Primal Hunter as more "draw a billion"s may be worth considering, since we run Momentous Fall/Rishkar's Expertise/Life's Legacy already. More redundancy is never a bad thing! Staff of Domination is another outlet that works with Magus of the Candelabra, or just a draw outlet with a bunch of mana.

For cuts, my recommendations would be Oblivion Stone, Krosan Grip (if we're adding more efficient interaction), Nissa, Vital Force, and possibly Homeward Path? Although I'm not certain exactly how many Mind Control effects you face down in your meta. Anything that has the ability to be a Forest but isn't instead should be putting in some serious work.

Anyway, I could be off base on some of these recommendations, but all in all I really enjoy the deck. Keep up th

I agree with adding Nature's Claim as a different piece of removal than Krosan Grip. I might still find a slot for K Grip at a later date, but for now I'll try Claim.

I had a Garruk, PH years ago but cut him for something else. I'm actually reasonably happy with the draw package I've got going on right now. Staff was something I hadn't even thought about until you mentioned it, and I'm shocked it isn't in the deck.

For cuts, I think I'm going to keep the Nissa in the deck, since she can work so well with the number of ramp spells I'm playing. If you can have her stick around for a turn, her emblem is nasty in this deck.