Thu Apr 26, 2018 5:13 pm  
Mad Ossam=Nightsong?

From the 2nd edition Dungeon Master's Guide (by David "Zeb" Cook):

The location of [Heward's] Mystical Organ is unknown, but the legends of several great and powerful bards relate to its discovery and subsequent loss... Mad Ossam was supposedly stricken upon trying to compose a tune at the Organ. Cursed with the power of blight and despair, he brought baronies to their knees in his travels.

Okay, now consider the description of the bard Nightsong, from Carl Sargent's Ivid the Undying.

Treltern is noted for a fine bardic collection of old poems and songs, surprising in such a small place; it was established by Nightsong of Delaric long before his alignment change, and indeed that legendary bard was born here. Few, however, would wish to see him return.

The most famous—or infamous—of the city's bards is undoubtedly Nightsong, a sinister but commanding presence at Montand's court. It is said that even Montand is somewhat afraid of the bard, whose power over his audiences is well-attested. Nightsong makes a habit of challenging guests with his recitations, and his innate evil is very clear from the relish with which he can skewer unfortunate victims of his displeasure with sarcastic barbs and veiled insults.

Nightsong is an accomplished magician, and his dungeons contain deadly traps and devices. It is rumored that Nightsong is an adept kidnapper, concealing his victims within the walls of his rank dungeons and holding them for ransom; he specializes in noble and wealthy adventurers.

Nightsong is consumed by a passionate desire for knowledge of all things and matters magical and mythical. With his amulet of the planes he has gathered lore and treasures from far beyond Oerth's confines. Nightsong knows the burial laments for the victims of the Invoked Devastation, the poetry of the necromantic invocations of the Ur-Flannae, and he can sing the whispering hymns of the long-dead Wind Dukes of Aaqa. Among his many magical items is a gold pendant which allows him to duplicate his own voice in harmony, an effect he uses rarely but to powerful impact. Nightsong is also thoroughly evil. He believes that all things come to nothingness in the end, though as usual with such nihilists he shows a marked dislike for the prospect of his own death. He reveres Tharizdun as the embodiment of this principle, though he does not actively worship him. He has been approached by a spy for the Scarlet Brotherhood, but as yet has declined to act on their behalf. Should he do so, the effect on Aerdy would be dramatic. Nightsong has little but contempt for Montand and could easily depose him and place Haragern in his stead, ridding Delaric of the military loyal to Montand and establishing the Brotherhood as the true power of the city.

Okay, so:

1. Great and powerful (19th level) legendary bard, check.
2. Formerly had some non-evil alignment, but underwent a dramatic shift, check.
3. Blight and despair, check, at least philosophically.
4. Brings baronies to their knees: well, he intimidates the prince of Delaric and has the power to change its government if he chooses.
5. "Nightsong" probably not his birth name. I mean, it looks like a supervillain name he chose after his alignment shift.
6. Interest in other planes of existence and ancient lore, check. Remember that Heward's domicile is supposed to be a planar nexus...

So: my verdict is that Nightsong is "Mad" Ossam, and his alignment shift happened after he played the wrong notes on Heward's Mystical Organ.

Also: likely affiliated with Planescape's Doomguard faction, at least as philosophical fellow-travelers.