|Dr. Yi Suchong|
|Suchong's Audiotape Image|
Dr. Yi Suchong, one of the opportunistic minds behind the creation and fruition of Rapture's Little Sisters and their guardians - the Big Daddies. Dr. Suchong was involved in Frank Fontaine's project to create a "trump" weapon, namely, Jack. Suchong implanted two verbal mind control triggers inside of Jack: "Would you kindly" which causes Jack to obey his commands without question, and "Code Yellow" which can ultimately stop Jack's heart. Dr. Suchong also developed an antidote, known as Lot 192, to Jack's mental conditioning, by request of Fontaine.
Suchong was also responsible for the mental conditioning that gave the Little Sisters the need to gather ADAM from corpses, as well as the creation of the Big Daddies and their mental imprinting that instructs them to protect the Little Sisters at all costs.
His corpse can be found in his clinic in Apollo Square, screwed to his desk by the Big Daddy drill that ended his research. He was killed by a Big Daddy when he became so frustrated that he slapped a Little Sister across the face, triggering the mental conditioning to protect the little girls.