Seven of Rings
Seven is a powerful magical number in many cultures: Seven deadly sins, seven virtues, Seven (rings) for the Dwarf-lords in their halls of stone, the number of chakras, etc.
Rings are things for binding: marriage rings, rings of atoms in chemistry, One Ring to rule them all, One Ring to find them,
One Ring to bring them all, and in the darkness bind them. (Ok, no more Lord or the Rings references, I promise)
The card consists of seven interlocking circles over a field of seven gradients from the pure white of light to the pure dark of the absence of light.
Meaning (upright): You have powerful forces bound to your command, but you must beware this much power is easy to lose control over.
Meaning (sideways/neutral): You stand on the edge, the forces of light to your right, darker forces to the left of you. Each seeks to bind you to its will. You need to balance this power or it could become your doom.
Meaning (reversed): Powerful forces are arrayed against you seeking to bind you to their will. If you allow them to tear you apart you will be left with emptiness.