Cheater!!! @_@

[Hguols]

In the earth lair, did you put a Invocation of Dreams into the pedestal of dreams? That's a hint right there. Have you been to the dark perspective earth lair yet?

I don't think any of the elemental staffs will be used a great deal. In all actuality, you could use the Earth Staff the most throughout the game, but not until you reach the Grimoire Grand Hall. Depending on how you play, you could use the Staff of Invoke Drain the most... and it probably won't be more than a handful of times.