The Trapping Mace (also sometimes known as the Screaming Mace or the Swearing Mace) is an elaborately carved weapon--technically a mace-and-chain--with an extremely unusual and cunningly layered openwork head. When found, the cagelike macehead will contain a small iron sculture of a disembodied head. This head will be a precise, small-scale likeness of the head of whatever being was last slain by the mace.
(If the last being slain by the mace had no identifiable head then it's the DM's discretion as to what's in there.)
Inside this head, the being's soul is trapped. If a new being is killed with the mace, the original soul is released, and the most recent victim's soul is trapped in the same manner, the tiny head warping and changing into the face of the new prisoner.
A trapped soul may, and generally will, speak, (it will telepathically be fluent in the owner's language) and--in nearly all cases--the soul is so eager to escape the mace and move on to whatever afterlife is proper to it that it will provide any information it has that might help the mace's owner successfully kill something else and thereby release it. Although the trapped souls will be, of course, angry with the mace's owner, the agony of existence in the mace is so exquisitely cruel that the trapped souls fear nothing more than the owner being slain and the mace being lost--dooming the soul to lie unfound in the unhallowed iron limbo for indeterminate years. Further, the trapped soul is magically bound to answer any question put to it (that it knows the answer to) and to tell the truth--though PCs may not be aware of this.
In combat, the mace acts with no bonuses, though it counts as a magic weapon.
The Teeth of Vorn are large and ancient swords--while the pommels, hilts, and guards vary widely, their long blades are inevitably hewn from what appears to be yellowed and black-veined bone. Priests of Vorn claim the blades were made from the rain god's teeth by his first acolytes, to protect his enormous form while it lay insensate for nine thousand years beneath The Dreaming Mountain. There were once 32 in existence, it is not known how many are left.
In practice, a Tooth acts as a bastard sword at -1 "to hit" (the character will realize this--the swords are unusually heavy and strangely balanced)--but once a Tooth has tasted its target's blood, it operates with a damage bonus of +1. Furthermore, with each successful hit thereafter, the blade gains another +1 damage bonus against that target or other targets of the same species. There is no upper limit to the damage bonus that may eventually accrue, but the blade will "reset" at the next sunrise.
This crimson product of Yuan-Ti alchemy is inevitably found in a double-stoppered vial. It has no effect unless two different living beings each drink a dose from the same batch. Once this occurs, any damage taken by either recipient* will be halved, and the other half of the damage will be applied to the other recipient. Likewise, any enchantments or other magical effects incurred by one recipient will affect the other, but at only half-intensity. Petrified recipients will find only the right or left halves their bodies turned to stone, recipients who have magically lost their sanity will be able to tell a hawk from a handsaw half the time, polymorphed recipients will be gruesomely hybridized, recipients may end up half-charmed, half-asleep, half-cursed, half-blessed, etc.
The effect is temporary, but a permanent version--known as the Oil of Tomacs--is known to have been developed.
________ *Except the damage dealt by the potion itself, of course. Don't be a dickhead.