—Lews Therin, referring to Rahvin, in Rand's mind.
Rahvin, (RAAV-ihn; /ˈɹɑː.vɪn/) formerly known as Ared Mosinel, was one of the thirteen Forsaken who were trapped at Shayol Ghul due to the Dragon's sealing. He used the alias of Lord Gaebril in Andor. His strength in the power is ++1, the highest ranking possible, putting him above all other channelers in the series except Rand and Moridin.
Rahvin was said to be as handsome as Lanfear was beautiful, with an insatiable appetite for the company of beautiful women. He had black hair, which was white at the temples. He was dark of complexion, with nearly black eyes. He was also noted for having a remarkably large stature; taller than Rand al'Thor, according to Mat, but with broader shoulders and a deeper chest.
Born Ared Mosinel, Rahvin always loved power, and was envious of anyone who held more than him. Interestingly, little is known of him before he joined the Shadow. Much preferring diplomacy over outright attack, Rahvin would most frequently use Compulsion and subtle manipulation instead of force. He was stronger in the One Power than Lanfear and was regarded as almost as strong as Lews Therin Telamon.
Rahvin turned to the Shadow because of his thirst for power. Through his manipulations he had several regions surrender without invasion. He was an efficient military general and a good governor, but showed a lack of attention to detail that undermined productivity during the War of Power. This carelessness can likely be attributed to his time spent with his lovers. Despite his incredible strength in the Power, he appeared not to have been of particular prominence among the Forsaken. He was also described as careful and meticulous.
Rahvin's first appearance is, although his identity is not revealed, when Perrin, while staying in the Mountains of Mist after the events on Toman Head, dreams of a meeting of Be'lal and Rhavin in a place resembling The Ways.
Perrin is unable to overhear what they're saying, but their gestures display mutual dislike and that Be'lal and Rahvin are arguing fervently. When a third man appears, possibly Ishamael, Be'lal and Rahvin briefly appear to take the same side against Ishamael, but soon their short alliance breaks.
Upon being freed from the Dark One's prison after the hard winter of 998 NE he moved to Caemlyn and styled himself Lord Gaebril, a nobleman apparently from the Mountains of Mist, and plotted to build a base of power for himself in Andor. When riots broke out in the city, he became the leader of the faction supporting Queen Morgase Trakand. He put the riots down, and Morgase promoted him to Elaida a'Roihan's old post of chief advisor.
Through the use of Compulsion, he persuaded Morgase to accept him as her lover and consort as well as advisor, insinuating himself into the palace political structure. Before long, Morgase was rendered powerless under his "suggestions." Rahvin kept her in what felt to her like a lovesick haze. She was virtually unaware of her surroundings due to the Compulsion and intent only on earning her "advisor's" approval by doing his bidding, even as he dandled another woman on his knee.
Rahvin urged Morgase to banish or arrest many of her most loyal supporters. Morgase was seen ordering noble allies flogged publicly, such as Ellorien Traemane. Most notably, at Rahvin's direction Gareth Bryne was removed from his post as Captain General and was sent into exile. By ostracizing Morgase's allies, pandering to her enemies, and generally undermining the public opinion of Andor's Queen, Rahvin set in motion actions to afford him the opportunity to control both Andor and Cairhien, through Morgase if not directly.
When Matrim Cauthon arrived in Caemlyn with a letter from Elayne Trakand to her mother the Queen, he unwittingly overheard a conversation between two Darkfriends, plotting the death of the Daughter-Heir. Only later did he discover that the mastermind of this plot was none other than "Lord Gaebril" himself. Mat took it upon himself to thwart this plot, following the assassin to Tear and killing him there.
On the throne
Rahvin experienced more trouble maintaining control over Morgase than he expected. News of the supposed revolt in the Two Rivers region, and a conversation with her old nurse Lini, snapped Morgase out of her besotted state. Consciously fighting the desire to comply with Gaebril's wishes, she managed to resist the Compulsion and escape the palace with the plan to coalesce support behind her again.
The rumors of Morgase's death at his hands led Rahvin to make his own claim upon the throne earlier than planned, with his personal brigade of soldiers, the White Lions, as enforcers. He also made plans to invade Cairhien and claim that throne as well. This plan formed part of his arrangement with Graendal, Sammael, and Lanfear, to lure the Dragon Reborn into attacking Sammael, at which point the four Forsaken would link in a circle and defeat Rand al'Thor.
However, all his planning was thrown into chaos when Rand heard of Morgase's presumed death. Rather than invading Caemlyn, he and a relatively small army of Aiel Skimmed into the middle of Caemlyn with the intent of obtaining revenge for Elayne, Morgase's heir. Almost immediately after the arrival of Rand and his forces, Rahvin killed Asmodean, Aviendha, and Mat with lightning, sending Rand into a fury and inadvertently causing him to remember how to Travel. Rand used this new knowledge to transport himself directly into the palace throne room, where he began a cat-and-mouse chase with the Forsaken. Harried, Rahvin entered Tel'aran'rhiod and Rand followed. There, Rahvin nearly managed to transform Rand into an animal of some sort using the reality bending properties of the dream world. However, Nynaeve al'Meara managed to sneak up on him and nearly incinerated him through Moghedien, who was being controlled by an a'dam. This distraction allowed Rand to recover and obliterate him with balefire, which had the effect of inadvertently undoing the deaths of Asmodean, Aviendha, and Mat. Having been struck by balefire, Rahvin was unable to be resurrected even by the Dark One.
Rahvin is probably based on the rakshasa (demon) lord Ravana, from the Hindu epic The Ramayana. Like Ravana, Rahvin is very attractive to women - illustrated by his seduction of Morgase and flirtations with other women in the court of Andor.