So I played a weird amalgamation of this deck and the Stompy lists. I started building the deck wanting to play Serum Powder + Eldrazi, but as I was building it, I really didn't like the colorless lists. I was going to go with the mono-red version of it but felt like Ancient Stirrings was just too good to pass up. So I ended up with a more midrangey combination of the two decks.
I ended up going 1-3 (had a bye round as well so "technically" 2-3) overall. I beat UW control and lost to Tron, UTron, and GB Rock. The UW game was honestly one of the most fun rounds I've ever played, I cast at least 8 Eternal Scourges in one of the games. This deck is pretty well geared towards beating UW. Scourge + Relic just makes their board clears useless, and targeting the Scourges just exiles them and allows them to be recast. They also put very little pressure on you so you have a ton of time to set up. There were 6 UW decks brought to the shop so I was sure I'd play against more than one. Unfortunately I didn't. The GB Rock game was interesting though, I heavily misplayed game 1 by cracking a Relic early just to draw a card instead of using it to rebuy Eternal Scourges as the game went on. I saw an opening to try and kill my opponent early and got greedy, if I had just kept the Relic around I probably would've won. Game 2 was a pretty quick victory, but game 3 was lost to early hand hate and poor draws on my part. This is the kind of game that I will probably win going forward as I get more comfortable with the deck. Anyway the Tron game was very close where all 3 games I put him down on life pretty quickly and managed to drag the games out (Crumble to Dust helps). Both his wins ended up being Karn, The Great Creator into Silent Arbiter, then getting Mycosynth Lattice. Without a Reality Smasher, Arbiter is an absolute hosing and I didn't draw into my Ancient Grudges in time. The UTron game was my last match against my friend playing my own deck and I was already out of the running based on my and my opponents' records. He played a Chalice of the Void on 4 then proceeded to play both Karn, the Great Creator and Silent Arbiter through it and neither of us caught it until 3 turns later. Since neither of us were winning any prizes we just played on and I ended up losing. Fun fact, in the game 2 against UTron I drew 17 of my 21 lands (I boarded out the 2 Gemstone Caverns while on the play for 2 Simian Spirit Guides). For my bye round, I watched my friend playing my UTron deck put an Oblivion Stone on top of his deck at least 15 times using Academy Ruins against Grixis Shadow and that was literally the only thing he did that game.
As far as my sideboard goes, I threw it together in a few minutes with what I could pick up at the shop/what I had on hand. The Simian Spirit Guides honestly felt pretty good, I almost always boarded out the Gemstone Caverns while on the play for Guides. Overall though, they are just a wasted sideboard slot for nothing more than a meme. If you can fit them into your deck to power out fast things, then great, but not at the cost of sideboard slots.
Overall thoughts: I really enjoyed the deck, Serum Powder and Ancient Stirrings make it so consistent to just start pumping out Eldrazi on turn 2. Eternal Scourge + Serum Powder/Gemstone Cavern feel so good when the stars all align and you can exile them for value. Scourge + Relic is incredibly powerful if you're going to end up in a grindy matchup. I didn't do well record-wise, but I'm happy with how it played. My local meta just has so much UW and Phoenix/Dredge are pretty prevalent too that I think this version of the deck is well positioned. There are at least 3 Titan decks too but that matchup feels fairly winnable with Obligator. If I were to change anything, I would probably swap the Serum Powders for Noble Hierarchs. Other than that I really liked the Scourges in my deck. Oh and I'd put together a legitimate sideboard.
4 Eldrazi Temple
4 Cavern of Souls
4 Karplusan Forest
3 Grove of the Burnwillows
2 Gemstone Caverns
2 Wooded Foothills
2 Forest
1 Stomping Ground
1 Mountain
4 Matter Reshaper
4 Eternal Scourge
4 Eldrazi Obligator
4 Thought-Knot Seer
2 Bloodbraid Elf
4 Reality Smasher
Spells
4 Ancient Stirrings
4 Relic of Progenitus
3 Lightning Bolt
4 Serum Powder
3 Crumble to Dust
3 Alpine Moon
2 Ancient Grudge
3 Kozilek's Return
4 Simian Spirit Guide
I ended up going 1-3 (had a bye round as well so "technically" 2-3) overall. I beat UW control and lost to Tron, UTron, and GB Rock. The UW game was honestly one of the most fun rounds I've ever played, I cast at least 8 Eternal Scourges in one of the games. This deck is pretty well geared towards beating UW. Scourge + Relic just makes their board clears useless, and targeting the Scourges just exiles them and allows them to be recast. They also put very little pressure on you so you have a ton of time to set up. There were 6 UW decks brought to the shop so I was sure I'd play against more than one. Unfortunately I didn't. The GB Rock game was interesting though, I heavily misplayed game 1 by cracking a Relic early just to draw a card instead of using it to rebuy Eternal Scourges as the game went on. I saw an opening to try and kill my opponent early and got greedy, if I had just kept the Relic around I probably would've won. Game 2 was a pretty quick victory, but game 3 was lost to early hand hate and poor draws on my part. This is the kind of game that I will probably win going forward as I get more comfortable with the deck. Anyway the Tron game was very close where all 3 games I put him down on life pretty quickly and managed to drag the games out (Crumble to Dust helps). Both his wins ended up being Karn, The Great Creator into Silent Arbiter, then getting Mycosynth Lattice. Without a Reality Smasher, Arbiter is an absolute hosing and I didn't draw into my Ancient Grudges in time. The UTron game was my last match against my friend playing my own deck and I was already out of the running based on my and my opponents' records. He played a Chalice of the Void on 4 then proceeded to play both Karn, the Great Creator and Silent Arbiter through it and neither of us caught it until 3 turns later. Since neither of us were winning any prizes we just played on and I ended up losing. Fun fact, in the game 2 against UTron I drew 17 of my 21 lands (I boarded out the 2 Gemstone Caverns while on the play for 2 Simian Spirit Guides). For my bye round, I watched my friend playing my UTron deck put an Oblivion Stone on top of his deck at least 15 times using Academy Ruins against Grixis Shadow and that was literally the only thing he did that game.
As far as my sideboard goes, I threw it together in a few minutes with what I could pick up at the shop/what I had on hand. The Simian Spirit Guides honestly felt pretty good, I almost always boarded out the Gemstone Caverns while on the play for Guides. Overall though, they are just a wasted sideboard slot for nothing more than a meme. If you can fit them into your deck to power out fast things, then great, but not at the cost of sideboard slots.
Overall thoughts: I really enjoyed the deck, Serum Powder and Ancient Stirrings make it so consistent to just start pumping out Eldrazi on turn 2. Eternal Scourge + Serum Powder/Gemstone Cavern feel so good when the stars all align and you can exile them for value. Scourge + Relic is incredibly powerful if you're going to end up in a grindy matchup. I didn't do well record-wise, but I'm happy with how it played. My local meta just has so much UW and Phoenix/Dredge are pretty prevalent too that I think this version of the deck is well positioned. There are at least 3 Titan decks too but that matchup feels fairly winnable with Obligator. If I were to change anything, I would probably swap the Serum Powders for Noble Hierarchs. Other than that I really liked the Scourges in my deck. Oh and I'd put together a legitimate sideboard.