They happen less frequently early in design, occuring every three to four weeks, and increase as the design evolves
Unfortunately, the playability of Gouging Fire-ex hurts its value quite a bit
Fiery Confluence, for example, can shatter up to three artifacts on resolution, or you can mix-and-match artifact destruction with one of its other modes
While cards that force your opponent to lose the game by not being able to draw from their deck have waxed and waned in Pokemon history, Moltress Wildfire attack was a strong option on that front in the TCGs early days
Create two 1/1 green Saproling creature tokens for each card of the chosen type revealed this way
It's also confirmed that a new art style is coming for ultra rare Mega Evolution Pokmon ex, which may feature a silhouette of the regular version of that Pokmon (for example, Lucario appears in silhouette on the ultra rare card featuring Mega Lucario ex)