The demon tilts it's head for a second.
Then it merely turns to face the dome and reaches out. The Shadowy demon's arm stretches and bends, and one finger extends to tap the dome.
A ripple goes through it.
Tap.
The dome flickers and roils.
Tap.
The dome shatters like glass to reveal the head cultist, who raises a hand. The shadowy demon is send back screaming as a bright light bursts from the head cultist's hand.
The demon flees to the hallway, hissing angrily.
“She'd become a governess. It was one of the few jobs a known lady could do. And she'd taken to it well. She'd sworn that if she did indeed ever find herself dancing on rooftops with chimney sweeps she'd beat herself to death with her own umbrella.”
― Hogfather