All the Transformers cards feature the mechanic more than meets the eye, which allows you to pay a mana cost to cast the converted version of the card
With each new anime series, a new mechanic has always been added to the game from the GX Era all the way up to Yu-Gi-Oh
Back in February we saw the first one, then another later on
Abrupt Decay Advent of the Wurm Aethermage's Touch Arid Mesa Basilisk Collar Blade Splicer Blood Moon Boros Reckoner Broodmate Dragon Cackling Counterpart Call of the Herd Cruel Ultimatum Cyclonic Rift Damnation Damping Matrix Deadeye Navigator Death's Shadow Desecration Demon Evil Twin Extractor Demon Falkenrath Aristocrat Fiery Justice Gifts Ungiven Goblin Guide Grafdigger's Cage Hellrider Marsh Flats Mind Shatter Misty Rainforest Mizzium Mortars Niv-Mizzet, Dracogenius Obzedat, Ghost Council Phantasmal Image Primal Command Pyromancer Ascension Ranger of Eos Restoration Angel Scalding Tarn Scavenging Ooze Sever the Bloodline Simic Sky Swallower Stoic Angel Stony Silence Summoning Trap Sance Terminus Thragtusk Ulvenwald Tracker Venser, Shaper Savant Verdant Catacombs Wort, the Raidmother Zealous Conscripts Zur the Enchanter
Illustrator: Souichirou Gunjima Grimer #215 Grimer (1-Star Shiny, Shiny Rare rarity) is the #215/234 card from the Pulsing Aura set in Pokmon TCG Pocket
I wonder if there were any special releases with unlimited cards