The Citadel of Chaos

As the drape falls, daylight streams in through the window.
You realize that you have lost all track of time since entering the Citadel.
The sun is a welcome relief after your many hours of darkness.
A thump makes you turn back towards your adversary.
He is lying in a heap on the ground.
You take a step forwards and he lets out a blood-curdling scream!
'The curtain! ... You fool! ...'
he gasps in a voice that is obviously weak and dying.
Evidently the daylight you have let in is sapping his strength rapidly,
and he is trying desperately to crawl into the shadows.
But he is too weak to move far and he slumps to the ground, face downwards.