I colored a bit outside the lines with this wondrous item for Pathfinder RPG. It has some rather complex rules going on and I’m not sure how game breaking it is. It’s a risky item to introduce for sure, unless you don’t have any aspiring necromancers.
Obsidian Ossuary
Aura strong necromancy; CL 16th
Slot —; Price 180,000 gp; Weight 1 lb.
DESCRIPTION
This foot long cylinder is fashioned from the blackest obsidian about three inches in diameter and is capped by two small infernal skulls of silver. It is also embossed with intricate silver filigree that contains imagery of two skeletal hands gripping the cylinder from opposite directions. It is filled with the powdered remains of an osyluth (bone devil) skull.
The ossuary may be used as the focus to cast animate dead. When an animate dead spell is cast using the ossuary, the caster does not need the material component and there is no longer a 25 gold piece restriction per Hit Die limitation. The spell is also treated as if it were cast within an area affected by desecrate (doubling amount of Hit Dice worth of undead created).
Additionally, while the caster is in physical possession of the ossuary, the Hit Dice worth of undead he can control is doubled. However, the additional amount allowed may only be applied towards undead created with an animate dead cast with the ossuary as the focus. Furthermore, all undead under the control of someone physically possessing the ossuary gain a +2 profane bonus to attack rolls, damage roll, and saving throws as well as +2 hit points per Hit Die.
The ossuary gains its strength from those who possess it. Anyone in physical possession of the ossuary has his current and maximum Hit Points are reduced by half. Upon the moment someone gives up physical possession of the ossuary, their original maximum (but not current) Hit Points are restored.
CONSTRUCTION
Requirements Craft Wondrous Item, desecrate, unhallow; Cost 90,000 gp