Modified from the original Selvala Brostorm list done by tw0handt0uch and asm.
The biggest change we're making is replacing the Memory Jar + Scroll Rack loop with Hornet Sting. Hornet Sting gives us an alternate win condition to attacking with infinite power creatures, and can also kill all the beasts we make by Beast Within-ing all our opponents' permanents.
Outside of some small scenarios, Memory Jar and Scroll Rack were never cards that I was particularly happy seeing. I would never ever want to Memory Jar unless I absolutely had to. It costs 5 Mana which can be a pain to produce, it takes away our hand and any useful cards that might be in there, and it gives all our opponents' seven chances to draw something that can end our combo turn. A Silence or a Swords or a Force or anything are all scary things. Scroll Rack was also most useful when I was already drawing cards. The loop win condition was the biggest reason for me to keep Memory Jar and Scroll Rack in the deck and removing them for Hornet Sting also opens up a slot, so we're shooting for some consistency in filling that slot with one of either a pump spell, a draw, or an untapper.
Hornet Sting even kills a few cumbersome hatebears, which is great!
The philosophy of my build is also going to be focused on the turn 3 dream, so I've cut the backup plans of Yisan and Priest of Titania, who were both too slow to reliably come out before Selvala herself. Although Sylvan Library shares this same attribute, it's staying in for now just based on how good it is.
Greater Good has come out and is being replaced with Harmonize. Greater Good was easily the weakest of our lovely green draw spells, shining only due to our scarcity of options and its repeatable ability. Losing our fatty is a big disadvantage, and although we can typically throw three lands away to the discard portion of Greater Good, that's not always the case. I'm going to be keeping a close eye on this change. I'm not completely sold on Harmonize, but we'll see.
A contentious addition is Paradox Engine. There's plenty of buzz about the card being and feeling winmore or dead in hand, but I have a lot of faith in the card. One of the biggest draws of Paradox Engine for me is that it makes every card in our deck besides the lands better, on top of enabling combos with some specific cards.
The first of these is Paradox Engine + Duskwatch Recruiter. Using Duskwatch Recruiter's ability, we can filter through our deck three cards at a time, putting every creature we come across into our hand. With Paradox Engine out, all the creatures in our deck become untappers and will almost always net mana depending on how big the fatty we have out is. Before Paradox Engine, Duskwatch Recruiter's only purpose was as an outlet to having infinite mana. Having to resort to activating Duskwatch Recruiter without infinite mana was typically a death sentence and announced to the table that you were dead in the water. Now, even with Duskwatch and Paradox, it is still possible to fizzle. There will be times when you spend all your Mana activating Duskwatch and just don't see a creature, but it's unlikely and only a small con.
The next great Paradox Engine interaction is Summoner's Pact + Paradox Engine, but almost any tutor that goes to the graveyard upon resolution will work. With Paradox Engine out, you cast Summoner's Pact finding Eternal Witness and untap Selvala. You tap her again for more mana, play Eternal Witness, untap, and return Summoner's Pact to your hand. You tap Selvala again for more mana, cast Summoner's Pact finding Temur Sabertooth and untap Selvala. You play Temur Sabertooth, untapping Selvala. From here you can loop Eternal Witness using Temur Sabertooth to untap Selvala and recur Summoner's Pact for all the creatures in your library and infinite mana. You can also do this with Chord of Calling and Natural Order. Eldritch Evolution unfortunately exiles itself and Green Sun's Zenith shuffles away.
Blossoming Defense and Mutagenic Growth are coming in to buff up our package of pump spells, with Blossoming Defense seconding as protection. Mutagenic Growth has a lot going for it, being free and all. It turns our 5 power dudes into 7 power dudes, granting us 7 mana, the magical number required to play and activate either Umbral Mantle or Staff of Domination with 1 mana left over to tap Selvala again.
I'm less sold on Blossoming Defense. It, Autumn's Veil, and Vines of Vastwood might all get replaced. Although incredibly spicy and great, protecting Selvala on the combo turn is actually slightly less important than protecting her during the turn cycle we have to wait to activate her. Rarely are we going to be able to play Selvala on turn 2 and also keep a green open for Blossoming/Vines/Veil. Most players are (correctly) looking to remove Selvala before we get to even untap with her, but it isn't uncommon for people to wait and hold what they have if given the chance. That sort of player tendency is what gives more legitimacy to keeping our green counterspells, so we'll see how things turn out with that.
The only two cards I'm really looking to find space for right now are Vitalize and Emerald Charm, and either one or both. I'm not sure which I like more than the other. Vitalize untaps everything but Emerald Charm gives us another out to Spirit of the Labyrinth, Rule of Law, and Eidolon of Rhetoric. It can also kill Food Chain and Necropotence and whatever else.
Thanks for reading all this way!
UPDATE July 12, 2017
It's been quite some time since I've updated my online list to reflect what I have in paper, so here we go.
Greater Good is coming back in. The draw is too important to be missing out on. Mox Diamond is out and I'm going to keep one of either Lotus Petal or Chrome Mox in to continue to test. I'm leaning towards Lotus Petal for now because it's free, but the downside that it's not a permanent mana source can hurt us real bad if that's what we're relying on to play down a t2 Selvala. We'll see where that goes in the future. Bane of Progress has come in over Reclamation Sage; in my games I was finding that if there was ever an artifact or enchantment keeping me from going off, there were more. Seeds of Innocence is another card that warrants consideration, but for now I'm testing Bane.
From Hour of Devastation we have Rhonas's Last Stand! Finally, another fattie. If we cut Hunted Troll and Groundbreaker from the original list, then their replacements are Phytoburst and Rhonas's Last Stand.
That's all for now. For those interested, I'll likely be making another update within the next couple of weeks.
