I see this being pretty damn playable, especially in versions of those decks that make treasures, can ramp with green, or can do big mana stuff with devotion and cards like Cabal Coffers
$1.29 Gloom 4th Edition $1.29 Funeral Charm Visions $0.69 Shrieking Affliction Return to Ravnica $0.79 Skittering Skirge Urza's Saga $1.49 Tormod's Crypt Chronicles $2.99 Black Vise 4th Edition $4.99 Withered Wretch Legions $6.49 Hypnotic Specter 4th Edition $1.79 The Rack 3rd Edition $12.99 Mishra's Factory 4th Edition $0.79 Diabolic Edict Tempest $2.79 Balance 4th Edition 0 results found
With enough mana you can poison someone for 4, and even protect it via regenerate
Kolaghan's Command is a great way to insure against artifacts without diluting your deck or risking dead cards
Leafeon V Ability: Greening Cells Once during your turn, you may search your deck for a [G] Energy card and attach it to 1 of your Pokmon
Water-type decks aren't the strongest type in terms of pure damage output, and their Lightning weakness means they're susceptible to speedy Lightning-type decks, which also have decent support