I like kevin's suggestion with Scion of Vitu-Ghazi . Sure it's better to do Advent into Wake the Reflections , but that's two cards, so you're losing out on card advantage.

That said, I do think Kalonian Hydra and Archangel of Thune are better endgame bombs. However, you claim you don't have the money for Voice of Resurgence ; but it's only a little more than those two. Obviously having all 8 would be best, but if you dropped the Hydra and the Angel in favor of 4x Voice the deck would overall be much better. And then, you could use the Scion in your 5-drop slot.

As for Armada Wurm , it's great but I think 6 mana is too much for a deck that only runs 4x mana accelerators (Elvish Mystic ). You should either let it go, or add more mana ramping. I think a great choice would be Sylvan Caryatid, which is coming up in Theros. Plus, didn't you say you were looking for more 2-drops? It's perfect.

Now, what to take out? I think you should lose Unflinching Courage . Without hexproof or indestructible creatures, you're pretty much asking for a 2-for-1. Not worth it. Also, maybe drop one Selesnya Charm (or move it to sideboard).

I also think you should undo the Giant Growth to Burst of Strength replacement. Giant Growth is better IMO, even with a Hydra out. Because let's face it, if you have a Hydra out, you're in a solid board position anyway, which makes Burst of Strength a win-more card. Giant Growth , on the other hand, can you help you when you're down.

Also, maybe 1-2 Selesnya Guildgate ? Just to balance out yourzcolors? Unless you choose to add the Sylvan Caryatid; then you probably don't need the gates.

Lastly, have you looked at Theros cards? Boon Satyr might work here; it could be a pretty decent Giant Growth -ish endgame bomb that leaves a body behind. Spear of Heliod might also be nice, pumping all your creatures and controlling the board. Soldier of Pantheon might be a nice 1-drop, and Glare of Heresy could be sideboard-worthy.

Hope that helped!

I will reconsider the Scion of Vitu-Ghazi . However, I'm kind of moving away from a token/populate deck. I will most likely be swapping the Call of the Conclave for Fleecemane Lion from Theros.

I still don't think Voice of Resurgence is worth it. Its literally twice a Kalonian Hydra and $15 more than Archangel of Thune . And I'm not sure it's as effective of a win con. In playtesting, I don't have any problem winning the first few turns. Its later game that I have problems, sometimes allowing opponents to stabilize. Both of those are much better finishers than a Voice.

I will definitely look at Sylvan Caryatid and any other mana dorks in Theros. I would have 4x Avacyn's Pilgrim but they're rotating.

The Unflinching Courage I really like. put that on an evolved Experiment One , Fleecemane Lion or Loxodon Smiter on turn 3, and it will win games unless the opponent deals with it. It puts immediate pressure mid-game, while buying me a turn or 2 to get to my bombs.

I'm still going back and forth between Giant Growth and Burst of Strength . I will need to playtest more. I probably won't go for the Boon Satyr tho, strictly because of mana cost.

I will probably throw in a couple of the Theros duel lands, as they are essentially guildgates plus scry.

I'll have to keep looking at the Theros cards, and may rework the deck a little once they are all released.