DEATH KNIGHT

The death knight — and there are only twelve of these dreadful creatures known to exist — is a horrifying form of lich created by a demon prince (it is thought Demogorgon) from a fallen human paladin. 

It has 18/00 Strength and usually attacks with a sword (80% chance of this being a magical sword). 

It will usually be riding a nightmare (see ADVANCED DUNGEONS & DRAGONS MONSTER MANUAL — Nightmare) one of which can be summoned to serve a death knight every ten years; the beast will serve a death knight as a paladin's horse serves a paladin. 

The fearsome powers of the death knight derive largely from its use of magic. Where appropriate, a death knight's magic use is at the 20th experience level.

It continually generates fear in a 5-ft radius, can create a wall of ice at will and has innate powers of detect magic and detect invisibility. 

Twice a day it can dispel magic and gate in a demon TYPE I (20%), TYPE II (25%),  TYPE III (30%), TYPE IV (20%) or TYPE VI (5%), with a 75% chance of the gate opening. 

Once per day a death knight can use any one of the power word spells, a symbol of pain/fear and generate a 20-dice fireball.

The death knight wears light armor (9" or 12" movement depending on its other encumbrance, if any) but is always treated as armor class 0.

The death knight itself cannot be turned or dispelled (though it is affected by holy word) but it has power over undead equivalent to that of a 6th level cleric.

It has 75% magic resistance, and if 11 or lower is rolled on percentage dice a magic spell will be reflected back at the caster (roll each time a spell is attempted).

A death knight will speak 3-6 languages in addition to its alignment tongue and the Common tongue.