RunningPigeon

I would consider sideboarding or even mainboarding Wheel of Sun and Moon, it'll help against graveyard hate which is a weakness in this deck; you'll basically be without a win-con if someone has instant speed graveyard exile and in modern you'll see that often enough.

I know it's out of the whole Wall kinda theme you've got going but I've found Assault Formation to be more effective without defenders; I've got a standard deck that uses Yoked Ox, Lagonna Band Trailblazer, Nyx Fleece Ram and some other high toughness 1/2 drops along with toughness buffing enchantments.
Always makes me feel warm and fuzzy beating an opponent down turn 4 with a bunch of livestock.

Oh also Sight of the Scalelords will work well for, as does Abzan Beastmaster; he's basically a 0 damage Dark Confidant in the deck.

Same here regarding getting Pauper partners, managed to convince one recently when we played this deck vs my Eldrazi Pauper deck which was fun.

Not too sure how competitive I would say this is, although did manage to beat proper Modern deck once, much smugness was had at the time, anyway good luck getting others in on it!

It's not too bad if you get 2 of them out and at the very least they can be cycle bait for the Homing Sliver, but it'll be something to get more of an idea after a full playtest.

Impact Tremors is a great idea, can't believe I didn't think to run it considering it's in my current standard deck as it is.
Also that Midnight Guard + Presence of Gond is brilliant, I won't run it in this deck purely because it's worth a deck in it's own right or maybe I will I dunno... either way it's a solid combo!

Duh why didn't I think of Impact Tremors, I even run it in my current standard deck oh well that's why it's always good to get another set of eyes on a deck.

Fair enough makes sense it is kind of powerful normally let alone in Pauper, ok lets grab Infiltration Lens for the draw.

Fair enough, the only other additions I might consider for the deck would be:
1. Familiar's Ruse, similar job to Deprive but adds re-usage of the Snapcaster.
2. Vexing Shusher for sideboard vs control/mirror matchups, might well be double red but making your spells uncounterable for mirror would probably offer an edge.

Any thoughts regarding Training Grounds to pump up the effectiveness of the Soulfire Grand Master?

Nah haven't played it; mainly since I don't have half the cards needed!
Generally I just like building decks like this on paper as a technical exercise, I'm pretty sure in play it's awful with only 4 Ravenous Rats as early game blockers it'll just get destroyed by anything with a turn 3 play or earlier.

Unfortunately it's not legal in standard so it's a no-go for now.... although if memory serves me right Archive Trap was in Zendikar and Battle for Zendikar will be coming soon sooo...... maybe it can be an inclusion soon.

I'm actually tempted to try it out on a game day, just to see if I can win a single round; could be funny with 4 Ornithopters, 2 Land and an Obelisk for a starting hand, maybe even draw into another Obelisk to get 4 of 4/6 flyers on T3.

You're right; there's no way to deal with threats in the deck, it was meant as a purely technical exercise in deckbuilding this is nowhere near competitive even at a casual level.
As for the Obelisk of Urd; well it has 16 creatures to buff and really there aren't many other options in colourless currently.... that and a potential 9/10 Keeper of the Lens was was too good to pass on!

Yeah the bow probably fits in as a potential replacement for the Learn from the Past, as for the Avatar as good as he is (and he really is good) he doesn't fit in with the mill mentality of the deck, it's combo deck after all I try not to attack once with this even if I get the Sage up over 100/100.

I'm with Vaan on this one; think you need Dragonlord's Servant or else you may fall behind on tempo against aggro and control decks even the Thunderbreak costs 4 which means control has up to turn 4 to get 3 land and counters/removal which doesn't seem unlikely, if you want to keep mana open for a counter then you're looking at turn 6 dragons at the earliest and giving control 6 turns with no pressure doesn't appeal.
Versus aggro decks again not sold on your tempo against them; Dragonic Roar is fine removal for early game but might want to consider Magma Jet for Crackling Doom it's easy cast it'll help vs many early attackers and help find the right land/spell to boot.

Good to hear it went well, I'm surprised by the inclusion of Eidolon of Rhetoric thought that it would slow you down, also useful was Windstorm? I've been thinking of adding it to my Assault deck to counter all the dragons but wasn't 100% whether it'd be mainboard or sideboard.

That's not a bad idea, not 100% sure what to drop thought, maybe Shapesharer; I'm just cautious about reducing the number of valid targets for the Call of the Kindred side of the combo and swapping out some of the land might make T1/T2 unable to hit any of the land fetches.... okay lets take it down to 2 islands; what could possibly go wrong!

Not really delved much into Legacy so my opinion might need to be take with a bit of suspicion but Phyrexian Unlife has always worked well with Melira, Ad Nauseam could potentially work too but it might be too slow even with Dark Ritual but it could make Kitchen Finks/Murderous Recap into only 1 of each being needed.

But like I said Legacy is not my primary game type so others may have better suggestions.

If you're looking at the Pinnacle being the win condition, then the Wurms might be able to be dropped.
Sylvan Caryatid might be one to drop too, could take Voyaging Satyr instead neither of them synergise with the Elves but the Satyr untaps land which can allow for Nykthos to be repeat used in a single turn.
Oracle of Nectars might be one to include too in place of Sheltering Word/Elderscales since with the high mana production in the deck it'll just produce as much life as you want plus it'll help with the Archdruid/Treespeaker.
Finally I think this deck will love Genesis Wave, if you drop the non-permanents you won't lose any cards and with all the Elves pumping up; hitting for 6+ on turn 4 is doable

So lets see maybe drop Wurms, Instants, 2 Pinnacles giving 14 spare, take 2 more Blooms, 4 Waves, 4 Doubling Seasons that's 10 so far then I suppose whatever feels right to you guess there might be room for the Wurms after all, that or Garruk (for more land untap) Elvish Promenade, an extra land or heck whatever there really is plenty of flexibility in the deck.

Only things I might think to add would be Doubling Season to quadruple the speed of Helix Pinnacle; dump 25 mana on Mana Bloom gives 50 counters, remove 50 counters pump Helix Pinnacle and there we go 100 counters, just imagine how little mana would be need with 4 doubling seasons out! (Turns out it's 1, yes just 1).

Gilder Bairn with a Paradise Mantle would also go infinite with Mana Bloom so long as the Mana Bloom has 7 counters on it when you set it all off to start with.

I did have something else for you but literally as I was typing I forgot what it was, it's gonna bug me but hey never mind, if it comes to me I'll repost!