Color: White and black creature
Location: A fantastical arch at the edge of the Underworld
Action: In Magic, an "archon" is a mysterious figure riding a winged animal. Start with the reference. Design a masked archon who can travel to and from the realm of the dead. Show a massive, fantastical archway inspired by Greek architecture. Its entrance is blocked with a "veil" of shadows. Show the archon and his winged mount emerging dramatically from these shadows. His winged mount is yours to design, but it shouldn't be a Pegasus. Maybe it's like an undead winged hound that's the size of an minivan.
Focus: The archon
Mood: He transcends the lines between life and death.