“ The PCs encounter a strange set of artistic drawings done on the ground as they pass through a city. It has been done in chalks and no one saw who did it. Wizards might recognize the writing within the colored square as an obscure and dead language with a message stating that a prominent wizard and a retired bard have discovered how to populate Arcadia with the spirits of the dead!
Is it a local hoax, or are the PCs crossing the path of a very deranged and possibly dangerous mage?”
“ Animals have parasites and diseases, so do plants, there are even bacteria that cann dissolve oil spills or plastic or what have you - why couldn't there be a disease living off magic - a magic item could be infected, losing power and speading the plague to other equipment it contacts, while a magic user would slowly lose his powers and contaminate all he works with or casts a spell at...”
“ Plant that is likely to produce allergic reactions in almost everybody, even by touch. Usage: medicinal, in very exotic foods, non-lethal traps, disabling opponents (have you ever cut an onion,anyway?), spell components, etc.”