POGIAMGEM = Presence of Gond + Intruder Alarm + Midnight Guard + Elemental Mastery

These four cards give you redundancy on both sides of a combo with Presence of Gond and Elemental Mastery both allowing tapping to create a 1/1 token creature, and Intruder Alarm and Midnight Guard creating the infinite loop of untapping our enchanted creature when another creature enters the battlefield.  Intruder Alarm requires an extra creature to make it all work, which Spellskite and Birds of Paradise provide in absence of Midnight Guard.  Elemental Mastery costs 1cc more than Presence of Gond, and doesn't win with Birds, but Elemental Mastery brings haste to the 1/1 tokens, so the end result swings on the same turn with either card, assuming you aren't tied up with only three lands/Birds.  With the right card draw, and no disruption, you can win on T3.  Just hope you aren't hitting your combo with Intruder Alarm, Elemental Mastery, and Birds of Paradise as your only creature.  Right now I have 7 cards on each half of the combo in the deck, but you can go 8 of each if you want, and be 98% sure you'll draw both halves in your opening hand, but risk getting four halves, meaning two excess cards that could help you better by being something else.  I also think 6 of each side works too, with one less each of Elemental Master and Intruder Alarm.  Maybe you have something you think is missing that can be inserted...

We're running five colors, so Birds of Paradise is a no-brainer, adding ramp to hit the combo a turn earlier if you can cast Birds on T1.  Spellskite protects your combo cards for the most part, while Shimmer of Possibility gets us to our combo quicker, or to a Spell Pierce or Spellskite for protecting your combo if it's already in hand (Note that Commune with the Gods makes another good option behind Shimmer of Possibility, as you see an extra card, and for this combo you're looking for either an enchantment or a creature, but then you can't get a counterspell or an Assassin's Trophy, etc).  Swan Song is extra counterspell protection at a minimal cost to keep our wincon reachable in the fewest turns possible, and in the early turns the biggest threat is another counterspell, a Fatal Push or Path to Exile, or an aura-jail, and Swan hard counters all of them for 1... the 1/1 creature should be of little consideration, just like using Forbidden Orchard; the game should be over before they matter.  Nicol Bolas, Dragon-God is a secondary wincon if you somehow find a stalemate in turns 3-6, creating quick card advantage and/or the removal of their legendary creatures or PWs, en route to his finale.

The land selection is hinged on tapping for any color, with G/U lands as "filler", but it's easy to take them out for more Mana Confluence or City of Brass.

The ratios of chosen lands and spells with redundancy are mostly split 4/2 versus 3/3 with the better of the two getting four.  But even so, this deck runs enough redundancy all over the place that it's fairly well proofed against Surgical Extractions and Extirpates.  Still, there's much room for shifting ratios to your liking or removing redundancy in favor of other cards/needs.

Also, this sideboard is an assortment of cards that might be considered for a real sideboard... i.e. this is not a real sideboard... and is temporary.