They joined the TCG in 2012 and feature visual changes like a superimposed Team Plasma logo and blue borders/details
For a Shadow the Hedgehog Commander deck, you'll be playing a ton of cards with haste as Shadow's effect plays with that alongside having a sub-Treasure theme to make all your spells unable to be interacted with
Pokemon Card Strategy: As far as strategy goes, since this is a basic Pokemon you won't have to wait long to put the defending Pokemon asleep, if I got this card out fairly early into the game I would try and put the defending Pokemon asleep, and then retreat Espeon for only 1 energy card and put a more powerful Pokemon into play that would be able to do major amounts of damage to that sleeping Pokemon without it being able to do any damage back

Green Badgermole Cub Badgermole Cub | Illustration by Nathaniel Himawan Creature (24) Badgermole Cub x4 Icetill Explorer x4 Leatherhead, Swamp Stalker x2 Llanowar Elves x4 Mightform Harmonizer x4 Sazh's Chocobo x4 Surrak, Elusive Hunter Webstrike Elite Enchantment (8) Earthbender Ascension x4 Sapling Nursery x4 Instant (2) Land (26) Ba Sing Se x3 Escape Tunnel x4 Fabled Passage x4 Forest x14 Promising Vein Sideboard (15) Keen-Eyed Curator Meltstrider's Resolve x4 Mossborn Hydra x4 Pawpatch Formation x2 Soul-Guide Lantern Surrak, Elusive Hunter Torpor Orb x2 This green landfall deck uses landfall cards like Sazh's Chocobo and Mightform Harvester very aggressively to create giant threats
Immersive cards have a unique grey swirling border to help make them more easily distinguishable, and when tapped on, they will begin an animation that gives a tour of the world beyond the illustration on the front
Summary More Universes Beyond collaborations coming, including Final Fantasy, Marvel's Spider-Man, and Avatar: The Last Airbender