A black magick incantation from Dark Shadows episode 762.  "I call upon the flame to summon you. I call upon the raven and the bat and all the dark creatures of nature, upon the charred and blackened clouds that reigned at your beginning." 

"They sink to the bottomless depths of corruption."  From Dark Shadows episode 210.

"I am what I've become.  I'll do nothing."  From Dark Shadows episode 7.

A hint of actor fatigue in the long-running Dark Shadows: "I've had just about enough of this nonsense I didn't write" (ep. 50) and "Nothing seems to go right, ever!" (ep. 56).

"That was before this."  From Dark Shadows episode 21.

"Ghosts and demons."  From Dark Shadows episode 14.  There was also that time that Liz Stoddard said the single word "Goblins," here.

"What do you want me to believe?"

"Nothing."

"All right, I believe it."

From Dark Shadows episode 53.

"Enveloped by a ghostly secret."  From Dark Shadows episode 1085.

"On this night, a kind of madness prevails."  From Dark Shadows episiode 364.

From Dark Shadows episode 658.

"I have lived so long expecting everyone to be able to do everything."  From Dark Shadows episode 495.

"Devils, be humbled."  From Dark Shadows episode 519.

"I don't know why I ever thought I could get through this."  From Dark Shadows episode 695.

It's no time to be funny on Dark Shadows episodes 244, 269, 1069, and 33.

"Goblins."  From Dark Shadows, episode 9.  There was also that time that Liz Stoddard said the single word "Ghosts," here.

"You will be consumed by the eternal fires of hell."  From Dark Shadows episode 601.

"I don't understand any of it.  I don't think I want to understand it."  From Dark Shadows episode 488.

As without, so within.  From Dark Shadows episode 10.

"If you're asleep, awake!"  From Dark Shadows episode 481.

"All I know is something did happen.  And the possibilities are horrifying."  From Dark Shadows episode 554.