Tsughos is feeling very hungry and faint, and now Japes is being forced to help her. (Should have read the fine print of that contract)

Now with difficulty settings. 

Easy: Max HP is 100, the goal is 100

Medium: Max HP is 70, the goal is 150

Hard: Max HP is 40, the goal is 200

How to play: Tsughos will be at the center of the arena, she will not move from her spot, her HP will start at 1. In order to win, you have to feed her until her HP is equal or higher than the goal. (She also cannot be stunned in this mode)

And what are you going to feed her, you ask? Don't be silly, it's you, of course.

The other ghosts (jealous of Tsughos plan, I'm sure) will constantly try to grab you for themselves. 

Besides the very real possibility Japes could just tell her to go to hell with her contract (granted, she's basically in it, but...), this actually sounds like it would be better served as a side mission to get the player to figure out how to herd ghosts to siphon large amounts at a time, since that gets you more HP.