The creation of intelligent magical weapons is not an exact science and there are occasional failures, as such think of causing a little more stress to your players by "rewarding" them with an insane magical weapon
Agrophobic, refuses to come out of the scabbard without a strength check to draw it.
Haemaphobic: afraid of blood, fight at a penalty against any blooded creatures but really good against undead, elementals etc
Schizophrenic, not just one mind in your sword, lets have half a dozen minds in there, all different and bound to cause confusion
the possibilities are endless
A nifty little encounter appropriate for any powerful sorcerer/magically adept monsters lair.
When the party have penetrated to an appropriatly impressive level/room they encounter The Door, this door is a vessel through which the Sorcerer/Monster can safely work against any intruders, the door is heavy duty iron bound studded oak wrought with craft skill and magic, set in the middle is a crystal orb, once the party get within a preset distance the orb flickers briefly as the door warns its "master" of the intruders, the master can then effectivly possess the door itself, this means that all movement the door is capable of (i.e. opening and closing) come under the control of the master, the master can also cast spells from the door as if he were there himself, all the while any damage that is inflicted in return merely damages the door, this will in effect ruin any of the parties chances of surprise, allow the master to assess the parties abilities while remaining safe and sound and finally will probably cause the party to waste some of their juicier items/spells on a chunk of wood and iron, and if the master happens to have a deadly spell or three it could also reduce the size of the party,
Of course if you wanted to be really nasty you could have the door open to admit one person and then slam shut on the second person (squish) whilst blasting away with every spell in the mastrs repetoir
Sages and naturalists frown at the common name given to these strange creatures by the small folk, but sometimes the silliest nicknames for creatures, places and people persevere in the minds of many. “Purifiers”, “Pond Jellies”, “Breath-Stealers”, “Lung-Ticklers” and “River Butterflies” are much less commonly heard appellations for these life forms. Wet Faeries are basically (and simply) a species of fist-sized, fresh-water jellyfish. Several traits steer them toward the peculiar category however. Firstly, Wet Faeries are nearly invisible in the water, much like their marine cousins but even more so. One can swim in a river swarming with these critters and not even notice their presence. Secondly, they possess the unique ability to clean and purify whatever body of water they inhabit. They do this via some sort of biological filtration process, sucking in all toxins present in the water, and releasing it back in its purest form. Needless to say, they are both a blessing and a curse to whichever folk dwell beside the rivers and lakes Wet Faeries inhabit. On one hand, no purer water can be found anywhere than a Wet Faerie lake or pond, and yet, in “pure” water “life” tends in fact to die out, lacking the needed nutrients to prosper. Thirdly, their “sting” is (unfortunately) virulently poisonous to all mammalians. Wet Faeries are loathe to sting anyone or anything, using their barbed fronds as a last line of defense, but if stung, most swimmers will suffer respiratory arrest, and die within minutes, usually drowning before they can make it back to shore.
Alchemists, druids, and less savory characters have studied these creatures over the years, and have predictably found all the ways Wet Faeries could be exploited. Morbidly humorous, some bards find it, that the Poisoners and Assassins Guilds as well as the Healer’s Union, all prize these creatures. The assassins use the extracted venom in obvious fashion, while the priests and healers use the still-living jelly-fish to sterilize other poison potions and to cure those already poisoned on death’s door.
It is known that a certain Earl Von Trumble keeps his vast castle moat stocked with Wet Faeries, the waters so clear that every bone of every one of his past enemies can be clearly seen on the bottom, twenty two feet below.