Qyburn was expelled from the Citadel for conducting unethical human experiments—specifically vivisection on living subjects. The Citadel stripped him of his chain, the symbol of a maester’s vows and knowledge. Though he retains the title colloquially (often sarcastically), he no longer adheres to the maesters’ code of ethics or their institutional authority.

Not in the magical sense. Qyburn stabilized Ser Gregor after Oberyn Martell’s manticore venom should have killed him. Through experimental surgery, pain suppression, and possibly alchemical intervention, he kept Gregor functioning—though mute, masked, and more machine than man. This “resurrection” is biological engineering, not sorcery.

He served as Master of Whisperers (replacing Varys) and later Hand of the Queen. He managed intelligence networks, oversaw the construction of wildfire caches beneath King’s Landing, and maintained Gregor as Cersei’s personal enforcer. His loyalty was transactional: protection in exchange for unrestricted research.

Yes—his character echoes Renaissance anatomists like Andreas Vesalius (who defied Church bans on dissection) and Paracelsus (a physician-alchemist who rejected Galenic dogma). Like them, Qyburn prioritizes empirical results over doctrine, even at moral cost.

In Westeros, maesters swear oaths to heal, not harm. Vivisection—especially on conscious prisoners—violates the fundamental tenet of “service through knowledge.” The Citadel tolerates theoretical necromancy debates but draws the line at active torture disguised as science.

Unlikely. Robert died from internal injuries sustained during a boar hunt—likely a ruptured spleen or liver laceration. Even with modern trauma care, survival would be uncertain. Qyburn’s methods required time and control; Robert bled out within hours, leaving no window for intervention.