Here's a unique budget combo deck you could give a try. Not the most competitive, but I did win a few games last time I used it in Modern. This is the updated version, using what I learned from playtesting.
If budget isn't a concern to you, a better land base could help this deck. Jace the Mind Sculpter might also have a place just for stalling your opponent.
Ideal game would go something like this:
T1: Land, Jaddi Offshoot
T2: Land, Fog Bank
T3: Land, Axebane Guardian
T4: Land, Freed From the Real, mana open so you can deal with removal/counters using Apostle's/Dispel. Make infinite mana. Devel's Play or Walking Ballista for game
Since you're unlikely to have all combo pieces, there's a few ways to get them:
-Commune with the Gods can not only dig for any missing piece, but could also drop a Devil's Play in the graveyard if you don't already have one.
-Drift of Phantasms can transmute to get either Axebane or Freed, whichever you need. Otherwise, it's a perfectly good blocker and can count towards the two defenders you need for the combo to go off. If you have achieved infinite mana but don't have anything to do with it, you can also search for a single copy of Sphinx's Revelation, and then draw your entire deck. At that point, finding a win con should be easy.
After playtesting, I believe I have refined an adequate sideboard, explained below:
Mind Grind: An excellent alternate win con against anything that runs Leyline of Sanctity (Each Opponent as opposed to targetting) or anything that prevents damage (Unlife/Solemnity combo, etc). The downside is that if you mill it with Commune, you can't still cast it like you could Devil's Play. But if you have Drift of Phantasms, you can still grab Sphinx's and draw your entire deck to find Mind Grind.
Aetherize: This is just to buy you a bit more time against aggro/midrange decks, as well as infinite token decks and maybe Storm if they use Empty the Warrens.
Back to Nature/Tempest of Light: Very good against enchantment control and Bogles. Although Back to Nature is clearly the better card here, I'm using different cards so that enchantment control can't simply Nevermore one of them. And if you use Sphinx's, you're almost guaranteed to have both in hand.
Negate: Can help shut down or delay some combos, like Scapeshift or Storm, or give you some extra counter-power against anything heavy in control/removal.
Grafdigger's Cage: Gives a very difficult time to Storm, Griselbrand, and anything else reliant on reanimation or flashback.
Pithing Needle: Good against many combo decks, like Griselbrand or Devoted Druid/Vizier of Remedies. In fact, this would completely shut down this deck by naming Freed from Real. Also good against planewalker-heavy decks.
Spreading Seas: Good for delaying Tron.
A few additional notes:
Mainboard, Walking Ballista is your only way around Leyline of Sanctity. Assuming you have infinite mana though, you can still potentially wipe out their side of the board so they have no blockers.
If you can afford to do so, adding a single Emrakul, Aeons Torn to the sideboard would be fantastic. In addition to being a solid Leyline-proof win con, it protects you from any mill decks you might come across.