. Spoiler
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Yes so when he raided the golden Triangle the professor initialized a psychological suggestion in Qin by creating visuals that the person he loved the most was drowning ( I think a drowning a fake body) in the river and that the people who he was trying to save, that is the hostages or the people affected by drugs were the cause of her very death. The professor wasn't entirely successful in completing the suggestion back then but the effect of it resulted in memory loss back then as well, when he forgot about the girl for whom he was in the esports industry and competitions and the person he was waiting for... So this time the professor actually succeeded in completing the suggestion as he showed him edited videos of her being killed and showing a video where someone was drowning with hands legs tied to a brick and again that the people weren't worth saving and they should be killed instead for causing the death of her... So when the suggestion was completed it resulted in complete memory loss, with behaviour change to being violent and ruthless and a person who won't think a second time before killing someone
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Bruh just give back his memories