The Seven Deadly Sins are the strongest & cruelest order of Holy Knights in the Kingdom of Liones. They were formed by seven brutal criminals, who had all been convicted for grievous crimes and had carved the symbols of seven beasts onto their bodies. They are the titular main protagonists of the 1st series. Meliodas, Hawk, Elizabeth, Diane, King, Ban, Merlin, Gowther, & Escanor started a new generation and have kids of their own for the future. The Loud family will have an adventure there.