Fun thing: both of the actors are originally just stuntmen. Both characters are evil and don't speak much. They have quite some things in common.
When I was high school my friends and I were at the grocery store late at night (because we lived on the edge!) and we saw this caffeinated drink called Bomba. The glass bottles looked like old school grenades and there was a pin you could pull to remove the sealed on cap. To our 16 year old selves it was coolest thing we ever seen. It tasted awful. We were hyped up that it would be great and it was disappointed. We had recently seen Star Wars Phantom Menace in the theaters. We called Bomba the "Darth Maul of beverages." Anything with wasted potential we called called the Darth Maul of ______. The Night King had a lot of tension and expectations to build him up followed by a disappointing anti-climatic death. The Night King is the Darth Maul of Game of Thrones. So was Bran's worg ability, the Iron Bank's implied coup, the Golden Company, and so much more.