I will be assembling this deck, as it is much better than the other combo deck I was planning on making.
My idea is based on two relatively easy to get cards:
Viridian Joiner and Umbral Mantle.
Neither are particularly awesome on their own, but added together you get an infinite mana combo that can go off as early as turn four.
Here's the basic plan:
1. Forest, Llanowar Elf
2. Forest, Viridian Joiner
3. Forest, Umbral Mantle, Orochi Leafcaller
4. This is the moment
Step 1 - Equip Umbral Mantle to Viridian Joiner.
Step 2 - Tap Viridian Joiner for 1 mana
Step 3 - Use that plus 2 mana from lands to untap joiner, giving him +2/+2
Step 4 - Joiner is a 3/4, tap him for 3 mana. Use 3 mana to untap him.
Step 5 - He's a 5/6, tap him for 5 mana, use 3 mana to untap him.
Step 6 - Repeat step 5 as much as you like.
Step 7 - Attack with Joiner, Blaze, Fireball, Drain Life, Kaerveks torch... Whatever.
Cool or what?