Hi, just in case people are wondering what in the heck my story is about, I'm sending these along...a few warnings.
This is lengthy, scholarly, and potentially quite boring. Read at your own risk.
Niniane - Niniane was the daughter of Dionas and was promised, by the Roman Goddess Diana that the wisest man on earth should covet her body and that she should be taught all that he knew as a reward. Daddy didn't seem to think so much about his daughter becoming someone's mistress, though, and either made her a Vestal (which would be buried alive for sexual indiscretions) or, in some stories, just threatens her with death. She does go off with Merlin (the wisest man) but goes to great lengths to avoid sleeping with him, although she does make the promise "teach me all you know and I will consent to anything you desire". She eventually kills him, either by trapping him in a tower of air, entombing him alive, trapping him in a tree, or sealing him in a cave after she has learned everything he has to teach her and has assumed his powers. She goes on to aide Arthur in everything, although she often appears just a bit too late to do the most good. (Which could be attributed either to absent mindedness, maliciousness, or perhaps both.) She tends to do things indirectly, usually sending knights out to do things for her and coming over only to do what only she can do. (Not a bad idea. Why needlessly risk a life?) Niniane is an accomplished hunter, and receives Excaliber from Arthur after he dies. She is the second Lady of the Lake, in which guise she adopts and trains Lancelot. (Not the Lady who gave Arthur the sword, however.) In later stories, she marries Pelleas, a nice, although not particularly bright man who manages to complete the Grail Quest. (He seems like a Gourry clone who is even more clueless about women...terrifying!) (Sources for character: mainly medieval, particularly the Vulgate cycle with bits of modern for the "ooops, did I do that?") In this story, I compare her to Eris and Zelgadiss.
Merlin - Merlin was born because a devil seduced a woman to produce the Anti-Christ. Luckily the woman was very pious and so her child turned out to be not quite the Anti-Christ…but he certainly had remnants of his demonic heritage. Merlin claimed that his knowledge of the past was from his father, his knowledge of the future from God. Merlin was an incorrigible trickster, who had a truly twisted sense of humor. He rarely appeared in his true form of (?) and "made" four kings, of which Arthur was the last of. His motives are sketchy and he's only a "good guy" because he's on the right side…some of the time. In the medieval versions, Niniane is applauded for disposing of him. All the same, he is a fascinating, if unruly character. He taught, besides Niniane, Morgan le Fey. (Sources taken mainly from medieval manuscripts, including the Suite du Merlin, the Vulgate, and Le Morte d'Arthur) Compared to Rezo and Xellos.
Morgan le Fey - When Morgan was only a small child, her father was killed by king Uther so that he could marry the Duchess Igraine, her mother. Uther and Igraine had a child named Arthur, who Morgan le Fey probably had more reason than the older sister to feel resentful towards him. When mommy married, Morgan's older sister Margawse was married off (at thirteen to a man old enough to be her father, or even grandfather!) while Morgan was sent to a convent where, according to Malory, she learned black magic. (Malory really liked the Church, can't you tell?) Eventually she married another king, Uriens and bore him a son, although she was none to happy with him. She took lovers and tried to kill her husband, although she was stopped by her son, Yvaine. She repeatedly tried to seduce and destroy the various knights, particularly Lancelot. Some of her most famous stories involve her trying to steal Excaliber or to point out Guenivere and Lancelot's little indiscretions. Niniane tends to thwart all of her plans, although Morgan's malicious gossip eventually gets through. (Niniane apparently thwarts everyone's plans.) Morgan eventually does team up with her archrival when Arthur dies as both bear him to Avalon. T. H. White has her as a fairy who lives in a castle of food, constantly eating and Morgan does seem rather fond of the more physical terms of life. (Information taken mainly from Medieval sources, particularly the Vulgate and Le Morte d'Arthur.) Morgan is compared to Lina with her fierce temper and boisterous eating habits.
Margawse - Margawse was the daughter of Igraine and the Duke, the sister of Morgan, and the mother of Gawaine, Gaheris, Gareth, and Agravaine by her husband Lot (a huge enemy of Arthur) and of Mordred by her own half-brother Arthur. Although in most stories Arthur is unwitting about this incest, Margawse's guilt changes with the author. In some stories she is actually defecting from her husband's side and falls madly in love with this handsome young man. In other stories, she is a spy, but still does not realize that Arthur is her own brother. In others, of course, she possesses full knowledge of what she does. When Arthur discovered what he had done, Merlin advised him to have all children born on May first destroyed (as that was the day that Mordred would be born) and so they were all set on a boat which was set out to sea. However, when the boat crashed on the rocks, only Mordred survived and was raised and later returned to his true birthright. Margawse was well known for her strong sexual appetite, and was killed while in bed with her lover by her son. (Incidentally, her lover was younger than most of her sons…) (Taken mainly from Malory's Le Morte d'Arthur) Margawse is compared to Nagha.
Igraine - Although Igraine is an adulteress in Arthurian legend, she is an unwitting one. When Uther seduces her to produce Arthur, it is in the guise of her husband. In fact, when she finds that Uther is flirting with her, she actually tells her husband to leave because she doesn't like the idea of that sort of thing. After Uther dies, she usually goes to a convent. Malory is filled with what a good and well behaved woman she was. How boring! (Sources used: Le Morte d'Arthur.) Compared to Sylphiel.
Gawaine - Gawaine is the eldest son of Margawse and Lot. Although he is originally the head knight, he is deposed by Lancelot and becomes stupider and more wanton. Poor guy. Gawaine is basically your nice guy. He's brave, cares for those he loves, and is willing to do what needs to be done, no matter the consequences (as the stories of Dame Ragnelle and the Green Knight might point out.) He is constantly having to deal with his aggravating younger brothers, and is the one, in Le Morte d'Arthur who insists upon the war with Lancelot as Lancelot has killed several of his younger brothers. Family ties are important to Gawaine. He also avenges his father's death and other such things. (Taken mainly from Le Morte d'Arthur, but also from Sir Gawaine and the Green Knight and various other folk tales.) Compared with Gourry.
Mordred - Mordred is the youngest and doomed child of Margawse and Arthur. From how he's treated in life, it might not really be all that surprising that Mordred turned out to be the villain in Arthurian legend. His father wants him dead and his mother is probably more concerned with men his own age…Mordred helps to spread the rumors about Guenivere and Lancelot's affair and stirs up trouble at almost every chance he can get. And yet, for however evil a villain he is, he's one of the few likable characters in Malory. Mordred is very intelligent and tricky. He eventually does manage to take over Camelot, and a massive war ensures. He orders his step mother Guenivere to marry him and locks her into the Tower of London when she refuses. (Taken from Le Morte d'Arthur and The Once and Future King, not that they're particularly different.) Compared to Xellos.
Guenivere - Forget about the modern sources. In medieval Arthuriana, Guenivere is a very spoiled princess who is a pain if she doesn't get her way. She chases Lancelot off from court repeatedly with claims of "you don't love me enough" and drives poor Arthur who really does love her stark raving mad. She never has children, and is tormented in some stories by her clone half sister, also named Guenivere. She's very athletic and may have come from stories of a shield maiden in her early history. (Taken mainly from Le Morte d'Arthur.) Compared to Amelia.
Arthur - Arthur, of course, is the great king of Arthurian legend, who the whole legend system is named after. He is brave, noble, good, self sacrificing, all of that. Perhaps his one lack of sacrifice comes to his wife, Guenivere, who he refuses to leave even though he needs legitimate children to inherit his throne. He's a fairly dreary character, really. (General) Compared to Zelgadiss, for lack of anything better.
The Bible states that after Jesus the Nazarene had died, a wealthy man named Joseph of Aramethea asked Pilot for his body for burial. He then placed the body into a tomb with all the proper ceremonies and had it sealed. Legend also states that Joseph possessed the cup that Christ's blood was caught in and perhaps even the spear that gave him his death wound. Joseph then traveled to Britain and, upon the isle of Avalon, planted his spear into the ground where a whitethorn bush bloomed. The cup, called the Grail, then was hidden somewhere and is guarded over by the Grail Kings, who are descended from Joseph's son Galahad. (Not the son of Lancelot, obviously.) However, the holy powers of the Grail could heal, give eternal life, spiritual goodness, and all of that. The idea of it probably came from a pagan Celtic cauldron which people were scarified into, but which was supposed to bestow important things like everlasting life and renewal. The cauldron is the greatest of the 13 treasures of Britian.
In Arthurian legend, an apparition appears of a young woman bearing the Grail. Someone (usually Merlin) then encourages the knights to travel for a year to retrieve the Grail. Only three (in Malory four) knights manage to be pure enough to find the Grail: Galahad, Percival, and Bors. (I think Bors…don't quote me. In Malory Pelleas also finds the Grail.) However, even this is not enough to save the land from the blight which is about to come.
Needless to say, between the Anti-Christ and the chosen follower of Diana, not to mention a score of well behaved Christians, religion in Arthurian legend is confusing. This is made more difficult in that both Morgan le Fey and Niniane are called fairies (someone who uses magic according to the Vulgate) and that, although there are two different sides, the sides seem based more on loyalty than blood and that characters are continually defecting. For example, although Igraine is good, both of her daughters are "bad" and her son is "good". Of course, although Margawse and Morgan are bad, Margawse is not unredeemably bad and tends to do some useful things for Arthur, as does Morgan, who eventually bears him away to Avalon despite her attempts on his life. Or what do we say about Merlin and Niniane? Niniane is obviously unloyal and a ruthless killer, but she saves Arthur's life on occasion. Both her and Merlin do save Arthur and his knights, but often appear too late to be of maximum help. Gawaine, Arthur's head knight for a while, is the son of Margawse, and apparently puts patriotic loyalty above familial loyalty as he leaves his mother in order to be Arthur's knight. (Most of his brothers join Arthur too, so....in fact, the one "bad" one, is Arthur's own son Mordred!)
There are continual feuds as well. King Claudus, Merlin's friend, decides to kill King Ban, the father of Lancelot. Niniane saves Lancelot and proceeds to attack King Claudus. Morgan conspires with Merlin against Niniane's friends, Niniane conspires with Merlin against Morgan, and Morgan and Niniane conspire against Merlin, all often in the same story! Morgan of course plots against Arthur, often with sister Margawse's help, and tends to use Guenivere and Lancelot as her tools. The whole plot is so filled with characters who are perfectly willing to use other characters to their advantage that it's hard to figure out what side anyone is on! However, most characters (perhaps Arthur, Igraine, and Gawaine aside) are more than willing to hurt another character to get what they want.