A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.
A rare branch of the arcane masters, encountered only among the deepest hill folk or ramshackle cabins, the Saucerer takes his power directly from the consumption of cheap liquor. Only the strongest, rankest, most nauseating of homebrewed alcohol will do, where it is instantly converted into mana available to the caster. Without a minimum level of inebriation, the Saucerer will be unable to cast any spells, as focus inhibits his spellcasting abilities.