A pure Wight Deck shouldn't have more than a single copy of this, due to the risk of drawing into it without having the Skull Servants in the Graveyard
So on its own, this Koffing card would be a solid starter Pokemon card to use in a psychic type deck, I would consider using 1 or 2 of these cards and trying to get them in the active Pokemon spot to start the game
C Common Echelon of the Fire Kings X TRAP Special Summon 3 FIRE monsters (1 Beast, 1 Beast-Warrior, 1 Winged Beast), 1 each from your hand, Deck, and GY, but their effects are negated, also destroy them during the End Phase
The card sees plenty of play in Cube, Commander, and even Pauper, and I think this value will hold or even go higher based on players' demand
Challenging deck-building assumptions is going to give players tons of room to experiment and be rewarded, in everything from Limited to Legacy
A Competitive Newcomer