When Khans of Tarkir was first spoiled, there were a number of cards that had people excited for their implications in eternal formats. Now we all know how powerful the delve spells like Treasure Cruise, Dig Through Time, and even Gurmag Angler are. However, at the time, one of the most exciting cards was Jeskai Ascendancy. This card created the possibility for all manner of interesting combos across Standard and Modern, but became a fringe strategy with the banning of Treasure Cruise, Dig Through Time, and Gitaxian Probe. That said, it's still an explosive combo deck that's more than capable of taking games off of decks that aren't packing enough early interaction:
Jeskai Ascendancy Combo - Modern | Tag33, 5-0 Modern League
- Lands (16)
- 1 Forest
- 1 Island
- 1 Botanical Sanctum
- 1 Breeding Pool
- 1 Hallowed Fountain
- 1 Steam Vents
- 1 Stomping Ground
- 1 Temple Garden
- 4 Gemstone Mine
- 4 Misty Rainforest
The idea here is relatively straightforward. You want to combine mana creatures, Jeskai Ascendancy, and cheap cantrips to allow you the churn through your deck. At some point, you'll put Fatestitcher into the graveyard and can start netting mana or tapping down your opponent's mana and blockers.
One of the strengths of the four-color version of this deck is that you have Sylvan Caryatid as a hexproof mana creature as well as Glittering Wish to give you more effectively copies of Jeskai Ascendancy. The exciting innovation in this particular build is the addition of View from Above. This card teams up with your cheap mana creatures to give you a quick way of going infinite with Jeskai Ascendancy. All you need are 2 mana creatures and you can cycle through your deck making your creature very large. As you dig through your deck, eventually you can loot away a Fatestitcher and win from there.
Of course, if your opponent has answers for your non-Sylvan Caryatid creatures, you'll still need a way to win. Enter Flesh // Blood. This is a card that you can Glittering Wish for in the event that you can't protect a creature that can attack. Other variants have played cards like Crimson Wisps to help with this problem, but a slot in your sideboard is much easier to give up than one in your maindeck, since you can reasonably expect to see most of your deck in any game that's going according to plan.
If you're looking for a combo deck that is comparable in speed to Storm but attacks from a different angle, Jeskai Ascendancy may be what you're looking for. You're able to win the game with similar speed, but are vulnerable to different kinds of cards. Cards like Thalia, Guardian of Thraben and Rule of Law are great against both decks, but hate cards like Leyline of Sanctity and Relic of Progenitus are much less effective against Jeskai Ascendancy. If the hate is getting too much to bear but you feel the need to combo, look no further.