I actually feel that for her cost, she's got a lot of potential if you can use some other cards to juice up her power on the side
Of course, that includes this one
ex Starter Set Marnies Morpeko & Grimmsnarl ex [SVOM] also includes six other Pokmon owned by Marnie: Purrloin and Liepard, Scraggy and Scrafty, and Grimmsnarl exs two pre-evolutions Impidimp and Morgrem
It is not very difficult to have three Fiends in the Graveyard in a dedicated Deck anyway
Dragon decks Dragon decks still arent really a thing, given there are so few cards, but for those brave enough to risk the multi-energy options with their Dragonites, theres now a Druddigon that hits for 90 and does 20 damage when hit, but thats literally the only new card
Robust narratives are critical to anchoring IPs, and prevent them from fading into obscurity as one-hit wonders