Light 20
3 Petrova
4 Pala Olesis
3 Mist Rias
4 Magris
4 Holy Awe
2 Rain of Arrows

Nature 14
4 Bronze Arm
4 Faerie Life
4 Natural Snare
2 Soulswap

Multi 6
4 Lukia Lex
2 Techno Totem

The strategy is to beatdown your opponent with Lukia Lex. Pala Olesis and Petrova act as power boosters to make creatures harder to kill with the latter acting as a back up attacker.

Mist Rias and Magris pretty much run the deck. 4 of each mana accelerator to ensure we always get them out a turn earlier. Mist Rias in particular also benefits from the Pala Petrova power boost.

Holy Awe and Snare are mainly there because of shield trigger but with the mana ramp, I feel like hard casting isn't bad esp for Awe which can result in the opponent's board being cleared due to the strong creatures.

Other thoughts:
Maybe there's too much going on and I should not bother with the multi civs and focus on the Pala Petrova combo?

Could replace Petrova with Cryptic Totem and make that the main win condition.

Sanfist and Terradragon Arque Delacerna could help vs discard but I think the combo of Rain of Arrows and an early, hard to kill Mist Rias should be okay.

Constructive feedback and relevant ideas welcome. Tried to build this without water...

. 3 copies of Awe and Snare is probably enough cuz it's dead cards against control, u can use Kolon instead. Since you don't run Water and can only start drawing with Mist Rias earliest at turn 4, you can run sanfist/arque. The deck itself needs a lot of setup, like Pala Petrova Mist Rias to get things going, but Lukia Lex is better to be used as an early beat stick/more aggressive gameplay
You could switch Lukia Lex for Sanfist so discard doesn't mess you up and go for the defensive wall

Edit: didn't see the rainbow cards oops

14 Nature is a 40 card deck is fine actually, and the 6 rainbows count as Green sources for T2 as well.

You probably want to add more 2 drops like Quixotic Hero and (maybe even Sol Galla for the race synergy) if you want to beat the opponent down. Otherwise, you won't be able to curve out and kill your opponent before he stabilizes.

Cryptic is definitely too slow and clunky.

Definitely Arque/Sanfist > Rain of Arrows if you're building it as an aggro deck. But if you choose to run Sanfist, you'll probably have to shave the Techno Totem to avoid having too many rainbow mana sources.