By comparison, the Jirachi, Exploud, both Rayquazas, and Latias/Latios were insanely easy to find (and they werent)
If a monster is Special Summoned from your opponent's Extra Deck, while this card is in your GY (except during the Damage Step): You can Set this card, but banish it when it leaves the field
Weaknesses: [G] x 2 Resistances: N/A Retreat Cost: [C] [C] How to Play: Start using Dark Slumber to disrupt your opponent's Active Pokmon, especially if they rely on big attacks
The Celestus if you can be bothered to track night and day gives you extra looting and incremental life gain
You can whip up all sorts of infinite combos with Kodama and a bounce land, with a notable one being Scute Swarm and Simic Growth Chamber
Blue and black are the two colors that interact with it most