[September of Short Adventures] Day 15: The Ship of Terror

The Ship of Terror

Synopsis: While traveling on the high seas, the skies above start to get cloudy. The temperature drops suddenly as a feeling of dread overcomes the ship. Members of the crew begin to display a foul attitude and the whispers of mutiny fill the air. And on top of it all, an overall feeling of dread comes over the party. Something is not right.

Background: During some rough waters, an ornate vase decorated with Oriental artwork and symbols overturned and the lid came off. The vase is actually an urn of phantom trapping, and contained a supernatural creature known by those who trapped it as an oni. The oni is a demon that operates on the Prime Material Plane by possessing an individual and using it's powers through its host. It lives to sow misfortune amongst mankind.

The oni has taken possession of the ship's captain, and has been using this disguise to take the ship off course as well as sow dissent with the crew through the overuse of punishment for the smallest offenses. To the party, the oni has been cordial. This way the PCs would be more likely to suspect the most vocal member of the crew as the wrongdoer. If the captain is killed, the oni will simply jump into the next nearest person and continue his work. The only way to stop the mutiny and the eventual deaths of everyone on the ship is to find the possessed individual, force the oni out, and re-trap it in the urn of phantom trapping. If discovered, the oni will run to the cargo hold to retrieve it's kanobou +2 for the final battle (see below).

Monster:

Oni

No. Appearing: 1
Alignment: Chaotic (Evil)
Movement: 240' (80') as an incorporeal spirit, otherwise as host
Armor Class: 0 as spirit, otherwise as host with a +2 bonus
Hit Dice:8
Attacks: 1 (by weapon)
Damage: By Weapon with bonus due to Strength (See Description)
Save: MU 8
Morale: 9
Intelligence: High
Hoard Class: None
XP: 1000

An oni is a demon that lives to cause misfortune. On the Prime Material Plane, the oni appears as a hazy, incorporeal monster standing 8 feet tall with a horned head, fangs and either red or blue skin. In this form, it can do little besides use its summon weather power or to possess a host using an ability similar to the magic jar spell, only the oni does not need an inanimate object to store it's life force.

Once in possession of a body, the oni grants its host incredible strength (18, or 18/00 if your rules uses exceptional strength). In this form, the oni gains access to it's other magical abilities. Once per round the oni can use the following spell-like abilities: cause fear, darkness, putrefy food and water, warp wood and resist fire. Once per turn, the oni may use cause disease, bestow curse, call lightning and control temperature (with a 100' radius). Once per day the oni may use insect plague, control winds, lower water and move earth. If forced into melee combat, the oni prefers to use a large two-handed iron -shod club called a kanobou that does 1d10 damage plus the host's bonus for exceptional strength.

An oni can be forced out by a cleric of at least 8th level. Oni, like undead, can be turned and are treated as vampires for such purposes. A separate turn attempt is needed for exorcising the oni from a host before turning it again to banish it.