There are a number of possibilities
Sparkling Crystal: helps remove an energy cost, making it easier for you to get your attacks off
I believe the art for Arwen here was one of the best, and certainly an all-timer for me
You can even create a spooky ghostly deck with Lunala EX, Giratina EX, and the Gengar line (EX/Bother version) for some extra zest
Black-Winged Dragon X DARK Level 8 [ Dragon / SynchroEffect ] ATK 2800 DEF 1600 1 Tuner + 1+ non-Tuner monsters If you would take damage from a card effect, place 1 Black Feather Counter on this card instead
Green knows its big creatures well, but don't be afraid to branch out for something like Scour from Existence, Magma Opus, and Into the Story