“ Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.”
“ A Mimic in the rather unconventional form of a weapon, can be used as a weapon and grows more powerful over time. If introduced to the party early it could make an unexpected betrayal. Skittering around like a terrifying insect.”
“ 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.”