Is “Seized the imperial seal and proclaimed himself emperor at Shouchun” true?
attested in history
According to Records of the Three Kingdoms, Book of Wei, Biography of Yuan Shu, Yuan Shu obtained the imperial seal and proclaimed himself emperor at Shouchun, establishing the reign title Zhongshi, which led to his isolation and defeat, and he died of vomiting blood.
Yuan Shu
In official history, he was a warlord at the end of the Han Dynasty who was extravagant, usurped the throne, and proclaimed himself emperor.