Like most Pokmon cards, the value of Shaymin depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Platinum)
Cards that get and care about counters like Fertilid or Forgotten Ancient will help you set up the ability to use Tayam
Unfortunately, my Space-Time Smackdown situation is far more dire
You can build your own kingdom in the Pride Lands, assembling strong characters to boost their Willpower
Tempo over time effects are easy in some cases such as a clean suspend card
Best Murders at Karlov Manor cards MTG Surveil Lands Undergrowth Recon Delney, Streetwise Lookout Conspiracy Unraveler Fugitive Codebreaker Analyze the Pollen Leyline of the Guildpact Vannifar, Evolved Enigma Kaya, Spirits Justice Lost in the Maze Were always happy to return to Ravnica