The point is to work with the elves tribal and +1/+1 counters at the same time. Joraga Warcaller and Master Biomancer are both key cards to let the elves grow to truly enourmous size.
I want to keep this deck semi-budget so I will refrain from using fetch lands (for now). This also means that I'm not going to include Deathrite Shaman, even though it's a really good card, the mana ramp won't work unless my opponents is running fetchlands.
Key card synergies:
Hardened Scales is a neat little enchantment that fits perfectly in this deck (though not really flavour-wise.) Every time you add a counter onto something via Master Biomancer, Bramblewood Paragon, Joraga Warcaller, Simic Guildmage, Winnower Patrol, Elvish Vanguard, Skyrider Elf and more...you can add one more of those +1/+1 counters! Having Hardened Scales out makes all of your creatures much more dangerous and cost-efficient.
Master Biomancer How can you not love this guy, he's one of the reasons we're adding U. For four mana he's a little expensive, but every other creature that enters the game after him that creature gets at least 2 +1/+1 counters on it, or more if you've pumped your Biomancer up with your anthem guys or Oran-Rief or Llanowar Reborn. Moving Counters onto this guy is a good move, but there are other, preferable targets. Unfortunately the Biomancer is most likely going to eat removal, if your opponents realize his value.
Bramblewood Paragon For two mana a 2/2 body is okay-ish already, but it comes with fantastic abilities too! All other Warriors you control enter the game with an additional +1/+1 counter on them, that are all of your tokens, and a good part of your regular creatures. As if that wasn't enough, it also gives every creature with +1/+1 counters on it trample, which is much appreciated, considering your genetically augmented Elves have little in the way of evasion.
Joraga Warcaller is another Key (elf, warrior) Card in this deck. Technically he's a one drop, but you want to add as much counters on him as soon as he enters the game. He's top priority for opponent's removal, and if he doesn't remove him, the Warcaller has a gross potential of pumping up your elves. Bioshift can help here to move counters from Elvish Vanguard, or you might take the slow route with Simic Guildmage.
Other top-cards include your anthem guys Elvish Archdruid, Imperious Perfect and to some extent Obelisk of Urd (not sure if I should swap that one out for Eldrazi Monument?)Anthems are always great but your druid allows for awesome mana ramp too and the Perfect allows for spawning tokens and board presence.
Elvish Vanguard and Winnower Patrol and Skyrider Elf generate tokens, that you can either leave on them (and make them big tramplers with the Paragon) or move on to other cards that benefit more from them, like the Biomancer or the Warcaller.
