The Blood King was an evil monstrous king who ran an illegal crime business. He lived in a giant castle and had an army of Blood Knights by his side to slaughter anyone who got in his way.
After the defeat of Mr. Jap, Popeye needed a place to call home. That is when Jafar told Popeye about the dreaded Blood King, who uses peoples skulls as tea mugs while committing crimes. The (at the time) newly formed Radioactive Uber Clan decided to stop this evil king. The RUC slaughtered the Blood knights and the Blood King took his sword and went after Popeye The Sailor.
After an intense fight on the top of the castle, the Blood King literally fell to his demise off the castle. Popeye decided to grab the Blood Kings mighty sword known as "Excalibur Demise" and raised it in the air, signaling his victory.
The Blood Kings castle now became RUC HQ. The Excalibur Demise now became a vital item in Popeyes room.