It creates a Boo creature token each turn, encouraging you to either grow the rodent with your plus ability or 'fling' it at the enemy with the minus
Though it turned out that when you follow the rules, Starmie wasnt a very good card at all
The upside is it only costs one mana, and can be used at instant speed right before your turn

Instructor: Favorite Card: Stellarknight Delteros Deck: Tellarknight Deck 3 Satellarknight Deneb 3 Satellarknight Altair 3 Satellarknight Vega 3 Satellarknight Unukalhai 1 Satellarknight Alsahm 1 Satellarknight Procyon 1 Satellarknight Betelgeuse 1 Satellarknight Sirius 1 Xyz Slidolphin 1 Infernoble Knight Renaud 3 Satellarknight Skybridge 3 Generation Force 3 Magical Mid-Breaker Field 2 Cursed Bamboo Sword 2 Golden Bamboo Sword 1 Reinforcement of the Army 1 Harpies Feather Duster 3 Stellarnova Alpha 2 Call of the Haunted 1 Fiendish Chain 1 Xyz Reborn 2 Darktellarknight Batlamyus 2 Stellarknight Delteros 2 Stellarknight Triverr 1 Stellarknight Constellar Diamond 1 Gagaga Cowboy 1 Gagagaga Magician 1 Gravity Controller 1 Isolde, Two Tales of the Noble Knights 1 Ferocious Flame Swordsman 1 Infinitrack Fortress Megaclops 2 Gouki The Powerload Ogre Deck Concept This is a Deck, that during the opponents turn, you can activate the second effect of Darktellarknight Batlamyus

You can't wait to cast the spell later in the turn
While there are nearly endless options to accelerate Psychic Energy to, Mewtwo ex [Paradox Rift] seems like a great attacking Pokemon, and you can deal massive amounts of damage with its Photon Kinesis attack that does extra damage for each Psychic Energy attached to it