The so-called Blood Fiend Sword Formation was a notorious unorthodox formation, renowned for its simple setup and immense power.
The principle behind the Blood Fiend Sword Formation was actually quite simple. Forty-nine foundation stones were set down, and the blood of Xiantian Martial Artists was used to nourish the longswords within them. Finally, a secret technique was used to make the swords absorb all the Xiantian Martial Artist blood within the stones, transforming them into powerful blood swords.
Once everything was complete and the Blood Fiend Sword Formation was activated, blood qi would surge into the heavens within the formation. The longswords nourished by Xiantian Martial Artist blood would automatically leave their sheaths and massacre every living thing inside, stopping only once the blood qi within the swords had been exhausted.
Originally, the Zhang Family had planned to set up the Blood Fiend Sword Formation around the Du Family before attacking them.
Once the formation was activated, it could directly slaughter eighty percent of the Du Family's disciples. Then they would use massive crossbows to shoot down the remaining martial artists. Finally, the Zhang Family would move in and wipe out every last surviving member of the Du Family.
But the Du Family's sudden attack this time had ruined the Zhang Family's plans, making the Zhang Family head grit his teeth in hatred.
One had to know that only three foundation stones in his Blood Fiend Sword Formation still had not been filled with blood.
The Zhang Family had over a hundred Xiantian Martial Artists, taking turns to draw blood after recuperating in order to refine the Blood Fiend Sword Formation.
The blood in those three foundation stones could have been filled in just one day, once three Zhang Family Xiantian Martial Artists had recovered enough to draw blood again.