“ 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 Cloak of Shadows that causes mushrooms to grow in its own shadow. A crouching theif might find himself in a ring of poisonous toadstools, an interesting thing for a sentry to find after the thief has left hiding place.”
“ One of the PC's falls in love with a woman who happens to be a necromancer...perhaps she/he is allied with a group working against the PCs?”