Possibly a defiler does not have to drain nature - although he would do it as his preferred source of energy, he could also (at least for minor to moderate spells) rely on "conventional" energy sources. This would prevent Echo's solution being used as the defiler would just refrain from draining nature for the simple spell.
It has potential, but a bit more work is needed to make it actually workable. 2/5 Go to Comment
I think that the congregation of the different nature religions for a great festival of nature has more potential than hunting down a defiler mage hidden in their midsts. See Echo's comment on the easy solution.
It would be more interesting to know why the festival has come into being, what occurs, why the people attend, and so forth.
If it is known that one of them is a defiler, have all cast but a simple spell. So easy. "Cast a spell to prove your magic ability, so that you may continue with the contest."
Mystery solved. 2/5 Go to Comment
A festival of druidic rites and initiation rituals, either old-school or new-take, perhaps with this basic concept but with all the juicy and necessary details, would make a fine sub indeed actually! Go to Comment
The Wizard-Brewers of the Old Empire stored memories in bottles of mead, passing their brightest ideas, most subtle magics, and most important decisions on to their heirs in bottles of oddly-flavored honey-wine. A cache of these ancient magical vintages has been unearthed, but does anyone dare drink from it? The ancient mead's creator is a complete mystery, as are the thoughts he left behind.