Teen Titans, Season 4

[It's revealed to Robin that under Slade's mask, is a skull]

Slade:
[after putting his mask back on] I'd rather you hadn't seen that. It's really only a temporary condition.

Robin:
What are you?

Slade:
Let's just say I'm currently incomplete. Time is running out. We must keep moving.

Robin:
I don't think so. Unless I get some answers, you're on your own.

[Slade pauses and turns back to Robin, who's folded his arms]

Slade:
It seems my luck with apprentices is most unfortunate.

[The flashbacks show Slade's death and Trigon's half-resurrection]

Slade:
Terra's betrayal should have been my demise. But I got lucky. Someone was looking out for me that day.

Trigon:
[in the flashback] Heed my command, and I will return what you have lost.

Slade:
It was a simple arrangement, actually. Do a few chores, and I get back my flesh and blood. And I must admit, the fringe benefits were most enjoyable. [pause] A pity things didn't work out as planned.

[Flashbacks ends]

Slade:
The moral of this story? Never make a deal with an inter-dimensional demon without a little protection.

Robin:
You didn't bring me down here just to save Raven. I'm also here to help save you.

Slade:
A deal's a deal.