Ok, so I'm running a campaign in which the 7 most powerful wizards (well into Epic levels) have been placed under some kind of Geas by the BBEG, who in this case is an evil deity.

Essentially, these 7 were prophecied to stop him, and when they initially reached out to attack him, he used a set of prepared Scry/Geas/Curse combos in order to 'lock away' his competition.

I am struggling to think of a combo which would be enough to stop an epic-tier wizard, but would theoretically be able to be broken by them (so the geas retains the juicy 'until task finished' modifier).

Can you have multiple Geas's on the same person, but with almost-but-not-quite-conflicting messages? If for example, you had a "Clean every stone in your tower during the day" and a "Soil, defile and deface every stone in your tower during the night" geas, would that work, especially if combined with a "Mute" curse? (Assuming the tower is large enough that they cannot do both or either in the time alloted, and as such would start to rack up serious hp loss or stat penalties)

And would it be possible to break a deity-level geas? If so, how?

Cheers for any help,

Sam