Following on from the Paldea Evolved set, the Scarlet and Violet era of the Pokmon TCG has received another expansion in the form of Obsidian Flames
Tapping lands for mana is the most common, but you can also have creatures, artifacts, and other permanents that can generate mana
Beholders have already been confirmed with the preview of the delicious Monster Manual card frame (congrats, Orms-by-Gore fans), and were very likely to also see Mind Flayers, Gith, Kuo-Toa, Yuan-Ti, and Displacer Beasts make their way into the set alongside new Kobolds, Owlbears and Gnolls
The only efficient options for removing him will be hard removal like Dragon Fire and Let It Go
Attach one Energy card per turn to any Pokmon in play (unless an effect allows more)