This is the engine that makes this deck go:

On paper we've 5 colors, but we're overwhelming Red, White, and Blue, with just the tiniest splash of Green (For
Zacama, Primal Calamity and Gaea's Blessing) and Black (Exclusively for Mastermind's Acquisition and sideboard shenanigans). Our blue is exclusively draw (I used to have just the smallest touch of counterspells, but those were cut to make room for the 2 extra copies of Sunbird's Invocation to qualify for the challenge).

So how do we get 5 colors? A lame deck that wins would put in Chromatic Lantern, but we're a cool deck that loses so we run Rupture Spire and Gateway Plaza instead.

We're light on creatures, but that's okay. The couple of creatures who are in there are thicc, and exist for defense mainly. The sideboard is full of fun janky garbage to get with Mastermind's Acquisition, feel free to subsititute your favorite janky garbage cards in there (Although personally I think it doesn't get much better than Thousand-Year Storm copying Unmoored Ego )

Game plan:

1) Protect yourself! Put up your Rekindling Phoenixes and flip your Thaumatic Compass // Spires of Orazcaes. Remove threats with your removal!

2) Power up and flip your Primal Amulet // Primal Wellsprings. Lightning Strike, Opt, and Gaea's Blessing cost just 1 with an amulet out, and the latter two draw to replace themselves on top of that.

3) Draw toward your Sunbird's Invocations using your Opts, Secrets of the Golden Citys, and Search for Azcanta // Azcanta, the Sunken Ruins.

4) Play Sunbird's Invocation and start dropping bombs out of your deck for free.

5) Has something gone wrong? Maybe an opponent cast an inconvenient Cleansing Nova and killed all our toys? Well we run two Gaea's Blessings, things going into the graveyard is a mere inconvenience.

Cool things this deck does:

1) When casting Star of Extinction with one or more Sunbird's Invocations out, cool things can happen. Maybe you pull a Firesong and Sunspeaker and gain several hundred life. Maybe you pull a Truefire Captain and kill your opponent on the spot. Who knows?

2) Speaking of Firesong and Sunspeaker, the synergy with Deafening Clarion is insane. Not only do you heal from the boardclear, but it triggers Firesong's triggered ability and gives that lifelink as well. Getting Firesong and Sunspeaker to stick is the main way we beat RDW (assuming we live to turn 6 anyway).

3) Spells cast for free from Sunbird's Invocation still contribute charges to Primal Amulet // Primal Wellspring. Unfortunately copied spells from Primal Amulet // Primal Wellspring and Thousand-Year Storm don't trigger Sunbird's Invocation additional times.

4) Niv-Mizzet, Parun loves copied Secrets of the Golden Citys even more than he loves Opts.

Misc Notes:

1) We run Gaea's Blessing, so any mill deck we face is a free win.

2) We run The Immortal Sun. People excited for War of the Spark coming soon? Well Planeswalker Time is CANCELED.

3) A big downside of Mastermind's Acquisition is that you only get one card out of your sideboard. Just one, even though it's full of fun stuff! For best results, always copy it with Primal Amulet // Primal Wellspring, and assuming you haven't put your own favorite cards in the sideboard, always pull your other Primal Amulet // Primal Wellsprings from the sideboard first so you can start grabbing cards 5 at a time on subsequent casts like a boss.