He stood in silence and in darkness wrapped,
A figure motionless, a shadow vague,
Girt with the terrors of his secret sword.
Half-seen in clouds appeared a sombre face;
Night’s dusk tiara was his matted hair,
The ashes of the pyre his forehead’s sign.
(Ref. https://incarnateword.in/cwsa/34/the-journey-in-eternal-night-and-the-voice-of-the-darkness#p138)
If we take it in conjunction with the line above, the description is of Yama as Kala, who is the shadow of Mahakala. Shiva destroys with compassion, Yama under compulsion. Mahakala is the guardian of Time who guards us in the Night. Yama is the executor of the will of Time who robes itself in the Night.
Affectionately,
Alok Da
