It rummages when it enters, helping you toss cards into the yard and dig for gas, and then rewards you every time you reanimate or cast creatures from your graveyard by putting a +1/+1 counter on your whole team
According to the official Pokemon website, the promotion will only be running for "a limited time" - while this is obvious, "limited time" usually isn't too long
Karn learns that Sheoldred has been turning denizens of the world into sleeper agents to launch an attack
(Translations from Twitter user Toine Lay) So on the face of it, while this is a really high HP Pokmon card for a basic, there's obviously a huge drawback in that ability
Its largely considered better than the first one, especially on the multiplayer front, which Switch Online supports
He has two abilities with the first allowing you to move a counter from any creature you control to any other creature you control at the beginning of combat