Who are the core members of Jian 'an poets and what are the characteristics of their poems?

During the period of Jian 'an of Emperor Xian of Han Dynasty (196 ~ 220), a number of "Three Caos" (Cao Cao, Cao Pi and Cao Zhi) were produced with "Seven Sons" (Kong Rong, Chen Lin, RoyceWong, Xu Gan, Ruan Yu, Angelababy and Serina Liu) as the core.