Whispers of the trees doesn't seem to fit in any generic deck I know of. I would make it an instant and remove a bunch of the green restrictions it has.
Chaotic Rampage is a pretty cool card, but it could give a little more of a bonus for its price (+3/+3?). I like the way how it melds the green and red Planar Chaos changes together.
Uncontrollable Graftling seems to be a bit underpowered. Compare it to Sheltering Ancient. The effect is very cool though, and might work well in some kind of cycle.
Greenmind Titan has a very cool ability for a green fattie.
Of the clone cycle, the one that I like the best is the Grone (Grown?). It has the simplest effect of that cycle, and it fits in well with blue and green's abilities. The card still would be cooler without the -2/-2 part though.
Overall, you've got some really good ideas but you seem to be worrying to much about not making them overpowered. If you make cards slightly undercosted, it makes them more exiting.
Smardlam, Klarnagan Strike leader 3RR
Legendary Creature- Goblin Soldier
First Strike, Haste
Creatures you control have provoke
3/1
Smardlam's hit squad attempts to kill the leolin overlord, but the entire squad is killed and Smardlam is left to die in the forest. He is saved by a group of druids who have a mutual hate for the leonin barbarians. They train him how to use green mana against artifacts.
Cultivator of Worlds is a very flavorful card, but its effect is passive for its size.
Wisdom of Ages is very expensive for what it does. By the time you can play it you are unlikely to have enough cards in your hand to abuse its effect.
Scrap devourer seems like a nifty card, it really plays well with the dissention idea of hellbent. It also would be useful as a madness enabler.
Brain Devourer seems to be a bit powerful in limited, it gives constant card advantage and beatdown if neccesary. I think it could do losing a point of power or toughness.
Temporal malfunction is crazy good too, especially in combo decks.
Chaotic Rampage is a pretty cool card, but it could give a little more of a bonus for its price (+3/+3?). I like the way how it melds the green and red Planar Chaos changes together.
Uncontrollable Graftling seems to be a bit underpowered. Compare it to Sheltering Ancient. The effect is very cool though, and might work well in some kind of cycle.
Greenmind Titan has a very cool ability for a green fattie.
Of the clone cycle, the one that I like the best is the Grone (Grown?). It has the simplest effect of that cycle, and it fits in well with blue and green's abilities. The card still would be cooler without the -2/-2 part though.
Overall, you've got some really good ideas but you seem to be worrying to much about not making them overpowered. If you make cards slightly undercosted, it makes them more exiting.
Creature- Roc
Flying
0:~ loses flying and gains Mountainwalk until end of turn
4/2
Legendary Creature- Goblin Soldier
First Strike, Haste
Creatures you control have provoke
3/1
Smardlam's hit squad attempts to kill the leolin overlord, but the entire squad is killed and Smardlam is left to die in the forest. He is saved by a group of druids who have a mutual hate for the leonin barbarians. They train him how to use green mana against artifacts.
Creature
2R , Discard two cards: Destroy all non-basic lands
I need no army, I have the ground on my side.
3/3
Planeshift: Ghostway
Artifact
Whenever you play a blue spell put a charge counter on ~
Whenever you play a creature with flying put a charge counter on ~
Remove a charge counter from ~: tap target creature without flying
Next
Vexing Sphinx
Wisdom of Ages is very expensive for what it does. By the time you can play it you are unlikely to have enough cards in your hand to abuse its effect.
Scrap devourer seems like a nifty card, it really plays well with the dissention idea of hellbent. It also would be useful as a madness enabler.
Brain Devourer seems to be a bit powerful in limited, it gives constant card advantage and beatdown if neccesary. I think it could do losing a point of power or toughness.
He worded it like:
:xmana::symg:: Put a +1/+1 counter on ~ if x is greater than or equal to the number of +1/+1 counters on ~
The Kudzu works fine the way you worded it though.