Azure Bond

With this ritual spell a caster places a magical bond or sigil on the body of a living subject as a curse, allowing them to compel the target to do whatever the caster wishes whether they are willing or not. These sigils appear as bright blue tattoos placed against a darker blue background of lines that appear to be a mixture of thorning plants and waves, usually inscribed along the sword arm of the individual being controlled. The brands reflect light in the same way that stained glass does, and they give off a dull blue illumination of their own, though this is noticeable only in total darkness. In normal daylight, a sigil may be mistaken for a “normal” tattoo, though one of extreme size and complexity. Each sigil seems to be made up of smaller, identical symbols, each of which has been reduced to a speck the size of a pencil point. 

The sigil remains as long as the caster and subject remain alive and it essentially functions as a permanent Geas spell or Charmed condition. On casting the subject can resist the spell on an opposed spell roll, the subject using Wisdom as its stat if it is conscious so the caster usually prefers the target to be comatose throughout the ritual and they are usually unconscious for several days afterward anyway. (Note that if the caster fails its spell roll to complete the ritual both the target and caster take 2d10 psychic damage and on a natural one the spell will backfire with the caster becoming the one controlled.)

When cast, the caster creates a trigger word which, when activated places the subject under the Charmed condition when in visual range of the bond holder. They can then be given complex instructions that they are compelled to carry out and then ordered to "forget" the order on a conscious level. Ignoring long-term compulsions (to go to a particular place, for example) will result in the characters feeling ill, taking 1d4 psychic damage per day because of wasting sickness for every day spent resisting these compulsions. Such penalties do not apply while the characters are actively seeking out the individuals responsible for their brandings.
The more short-term orders (such as slaying the King of Cormyr when the bearer hears his voice) can be resisted if the bearer makes a DC 15 Wisdom saving throw.
The magic of the sigil starts very strong but weakens over time. To reflect this, the first saving throw against any specific short-term order is made at -6 to the die roll. The second such saving throw (whether against the same or a different short-term order) is made at -5, the next at -4, and so on, until the penalty is removed and the bearer is saving as normal versus the effects of the sigil. Making the saving throw indicates that the individual has resisted the effects of that particular order.  If the order is given again by the bond holder in another encounter (or if the situation causing that order arises again), then everything resets at -6.

If the sigil bearers are PCs operating under a long-term compulsion or a short-term order, the DM may either choose to play the characters as NPCs until the moment passes or may choose to let the players continue to run their characters under the effects of the order. Such activity may be detrimental to the character’s continued good health (and thus against the basic nature of the player running that character), so in recognition of a sincere and successful attempt to role-play a character under a potentially harmful compulsion, the DM should consider awarding bonus experience points (100 xp per encounter is suggested) to any character whose player demonstrates this sort of good roleplaying ability.

Attempts to remove or gain information about the sigils through magical or clerical means will be resisted by the magics in the bonds. The bonds are totally resistant to spells directed against them (as opposed to spells that are directed against the individual who has been branded) and the bonds have their own protections against being removed:

• A windstorm will start up in the area occupied by the spellcaster when the removal of a brand is attempted, whether from the arm of the spellcaster or another character. Loose objects will be cast about, and there is a 60 percent chance an object will hit the caster, breaking the spell and possibly (DM’s judgment) harming the caster.
• The character who has been branded must make a DC 20 wisdom check, or be overtaken by a berserker rage and a desire to slay the spellcaster which will last for 2-8 minutes. This effect does not occur if the spell caster is the target of his or her own magic.

Dispel Magic, Greater Restoration or Remove Curse will never have any effect on the brands, except to bring about the results mentioned above. A Wish spell (if successfully cast) will remove one sigil from one individual. Short of that, the Azure Bonds will prove extremely difficult to delete. Attempting to cut off the arm and regenerate it through magic will result in the sigils merely reappearing on the new limb. Dieing and being subsequently resurrected might just work but is a somewhat extreme solution, it's simpler to just have someone kill the bond holder.

The two bonds illustrated in the adjacent picture are complex ones made from the sigils of multiple individuals who co-operated in the rituals that created them. Both were created in the Moonsea region of Faerun about the year 1371 DR.

• The "Knife Surrounded by Fire" sigil that appears on both belonged to a guild of thieves/assassins called the Fire Knives that operated in the Kingdom of Cormyr in the 1360s and `70s DR until King Azoun IV put an end to them. These bonds were intended as assassination attempts on the King by remnants of the guild, both of which failed due to Azoun using a body double.
• The "Open Hand with Mouth" sigil, again on both is that of the ancient banished god Moander, also known as The Jawed God, whose cult seeks to bring him back onto this plane from the realm where he has been banished since the death of his mortal form. It is generally believed that this being was destroyed in that other realm after the creation of this sigil but, with gods that can never be certain.
• The "Insect Squiggle" is the sigil of an evil sorceress named Cassana who may be the creator or re-discoverer of the Azure Bond spell. She lived in the city of Westgate in the late 1370s DR but was believed killed in the year 1371 DR during a combat between an enormous dragon and an unknown entity (which may have been Moander) over the city in that year.
• The "inverted triangle and Z" sigil is that of the Zhentarim which needs no further explanation as that organisation is well-known and still active.
• The "Three Interlocked Rings" sigil appears to be that of a Wizard called Zrie Prakis. He was a former lover of Cassana but was believed killed by her some years before her death. There are rumours though that he continued to exist as a litch after death.
• The "Upturned crescent has been identified as being that of a renegade Red Wizard from Thay called Dracandros the Mad who was active in the Dragon Reach area at the time the sigils were created. Not much is known about him.
• The "concentric circles or "eyeball" is believed to belong to a fiend from the lower planes called Phalse (clearly a fake identity) who took the form of a halfling. Nor much more of him is known.
• The last symbol on the left-hand bond has been identified as that of an extra-planar being called Tyranthraxus. He is known to have caused trouble in the Moonsea region for untold centuries with the oldest stories about him fading into myth.

These are all the symbols that have been identified but, it should be noted that the bonds on the right may have space for an additional sigil that appears to be blank. This bond was carried by a famed adventuress called Alias of Westgate who made a name for herself in Cormyr, Dalelands and the Moonsea region in the later 1300s DR. She played a key roll in ridding herself of the curse but observers noted that the bonds remained afterwards but were blank though later aquired a rose sigil in the bottom location.

-------From Notes on the Azure Bonds by Rovaar of Candelkeep, 1494 DR--------