“Together we can be invincible.”
Saruman, also known as Curunir, is a character who is mentioned in Middle-earth: Shadow of Mordor and the one who possesses Queen Marwen. In Middle-earth: Shadow of War, he is indirectly referenced several times.
One of the Istari sent to Middle-earth, Saruman's initial purpose was to guide the Free Peoples of Middle-earth against the returning Shadow. Abandoning any faith to his mission, Saruman devoted himself to studying and coveting lore of the secrets of Sauron's power, especially the One Ring. Finding himself in thrall to the Dark Lord, the White Wizard strove, by terrible means, to either acquire the Ring for himself or become Sauron's most-trusted servant.
At the beginning, Saruman was one of the Maiar serving Aulëthe Smith, being only less skillful than Mairon the Admirable, until the latter fell and became Sauron. When the council of Manwë took place in the middle Second Age, the Valar decided to send five emissaries to Middle-earth to herald the Free People's fight against the malice of Sauron. Saruman volunteered, while Gandalf was commanded to do so by his lord, Manwë. To please Yavanna, Saruman took Radagast with him, in spite of his own distaste for him. Arriving in the Third Age, Saruman followed the Blue Wizards into the East to wrestle the remnant of Sauron's hold over the peoples of Rhûn. After one and a half millennia, he returned to the West, just as the Dark Lord's power grew in the fortress of Dol Guldur. Upon the formation of the White Council Saruman elected its leader, though Lady Galadriel had her reservations. Sensing the rising tide of evil and believing it was none other than Sauron, Saruman secretly turned to learning lore of the Enemy. Bewildered, awed, frightened and fascinated by Sauron, he came to admire him and desire to achieve perhaps the same power.
His time spent examining ancient arcana in the archives of Minas Tirith revealed the existence of a Palantír in Orthanc and so he later asked Steward Beren of Gondor for permission to settle in the Stone-Tower. Allowed to do so by him and King Fréaláf of Rohan, Saruman faked his commitment to the "alliance" protecting the West and instead delved into forbidden arts, even trying to see through the Palantír located there. As Gandalf's quest to weaken Sauron's strength in the North began, Saruman also started looking for the One Ring in the Anduin, thinking the Dark Lord's return might allow the Ring to show itself in time. He finally consented to an attack against Dol Guldur due to suspecting Sauron is one step ahead of him in the search. Fearing the threat of Sauron, Queen Marwen went into the Grey Mountains, where there she presumably met Saruman in one of his travels. When she returned to Núrn, she carried with her an elixir and through becomes susceptible to the will of Saruman. Her possession causes her to wither and make her seem older than she looks.Through Queen Marwen, Saruman speaks and tries to manipulate Talion and Celebrimbor. He is also behind some of the Morgai Flies nests that infest many of the Orc outposts, which he uses to spy on the forces of Darkness.
In order to obtain Celebrimbor's hidden knowledge of ring making, and possibly learn the whereabouts of the original, Saruman reveals himself and attempts to absorb Celebrimbor into Marwen's magical staff. Talion is stunned while Celebrimbor is ripped from his body, leading Marwen's daughter, Lithariel, to break the staff, freeing both Celebrimbor and Marwen from Saruman's control. As soon as the staff is broken, color returns to Marwen's hair and face, and she grows visibly younger. It did not take Celebrimbor to understand that the White Wizard's ambition was to try become the Lord of the Rings, of which there can only be one.
Once Sauron declared himself openly and gained possession of the Palantír of Minas Ithil, he established contact with Saruman. Through his lust for power, jealousy of Gandalf and admiration of the enemy's devices, the White Wizard was dominated and became subservient to the Dark Lord. Though a minion of Sauron by his vassal covenant, Saruman did not abandon all hopes of claiming the One Ring. Certain of his master's conquest of Middle-earth, he schemed to play a part in it to rise at his side and potentially cheat him if the opportunity to seize the Ring appeared.
Fortifying his fortress of Isengard, forging strong alliances and building his army, Saruman also recruited several Orcs of Mordor to act as his eyes and ears within the Black Land's borders, intent on discovering more of the struggle between the Bright Lord and the dreaded Nazgûl, hoping the raging battles may at the very least weaken both parties.
Marwen's ailment due to Saruman's poisoning mirrors that of King Théoden of Rohan's years later.