Hello guys! This deck is going to involve one of the very few "infinite" combos in standard right now. I say "infinite" because its limited by your deck size, but as long as you have more cards in your deck then your opponent has life total, it'll work without a problem. The beautiful thing about this is that 2 of the 3 combo pieces, Benthic Biomancer and Glint-Horn Buccaneer do not look out of place at all in a normal Jeskai cycling deck.
Here's how the combo works
1) Heliod, Sun-Crowned (or occasionally Splendor Mare) gives lifelink to Glint-Horn Buccaneer
2) Either find a way to gain life, or cycle a card, which can be jump started by adapting Benthic Biomancer
3) Glint-Horn Buccaneer deals one damage to your opponent, healing you one life
4) Because you gain one life, Heliod, Sun-Crowned places a +1/+1 counter on target creature you control ahem Benthic Biomancer
5) When the +1/+1 is put on Benthic Biomancer, you draw and discard a card, and go back to step 3
3 card combos are usually rather hard to assemble in a competitive environment, but thankfully it fits within a cycling deck, whose sole purpose is to sift through your deck incredibly fast, making it much easier to come across your combo pieces. A few cards in this deck are very rarely if ever hard cast, those cards are Drannith Healer, Frostveil Ambush, Startling Development, and Splendor Mare. In mid-late game, I actually find myself hard casting Boon of the Wish-Giver somewhat often, it's really good for when you cycle into a full hand of lands, you just stall out, or need to get that extra defender out of Ominous Seas
For a budget version of the deck, the best place to cut costs would be the shock lands. Having 4 of each combo piece is too important to cut, and the shock lands are the only real pricey cards besides Heliod.
Feel free to leave any suggestions in the comments. Have fun, and happy cycling!
Edit: After a day of playing this deck on arena, I've found some incredible success, with the only problems this deck having being facing mill decks and facing life gain decks, as those are the two main ways to make your library smaller then your opponents life total. To remedy this, I'm adding back Zenith Flare, a card i previously thought i could get away with cutting from a normal jeskai cycling list, but proves to still be a vital alternate win cond to keep in the deck. I added 3 copies by taking out 2 Frostveil Ambush and 1 Ominous Seas
Edit 2: After about a week of playing this deck on arena, I've went from silver to platinum 4, and I'm still winning lot of games so it could probably push me a bit further. I've also messed around with adding a few copies of Splendor Mare. It's worked really well so far into aggressive decks by turn 2 cycling a lifelink counter onto a turn 1 Flourishing Fox. That scaling life gain has helped sustain into the late game very well, and I'll update again if i decide for certain to keep it in.
Edit 3: Permanently put in Splendor Mare, the sustain is incredibly valuable
EDIT 4 (CORE 2021): added 3 copies of Teferi's Ageless Insight by removing 1 of each combo piece. I previously said that having 4 copies of each combo piece was too important to cut, but that was before this beauty of a card was released. It literally doubles the speed at which you sift through your deck.
