"Black Cube" - wonder what they're going for there. Maybe "Sinister Obelisk" was taken.

It's Saturn worship. Judaism is Saturn worship (all Abrahamic religions incorporate some worship of Saturn) - thus the obsession with black cubes, the number six, etc... There is no Star of David in the Bible - only the star of Remphan (a Saturnian deity). The god El is commonly associated with Saturn and commonly referred to as Saturn El. Saturn is the planet of limitations, constraints, agriculture, grain, the color black, etc... Thus the black cube is very fitting. If you look around hard enough, you'll find the symbolism everywhere.

https://en.wikipedia.org/wiki/Remphan

Remphan - Wikipedia

Isn't Islam the one with the Black Cube?

Judaism also has important black cubes in the form of tefillin worn by adult male jews during one of their daily prayers on weekdays.

https://en.wikipedia.org/wiki/Tefillin

Tefillin - Wikipedia