After Song Wen replenished the essence blood within his body several times, the pattern in midair finally took complete form.
It was an exceedingly profound formation, gleaming with blood light. Countless runes flickered unsteadily, bathing the entire cave dwelling in a blood-red glow.
At the center of the formation, a blood-colored vortex slowly revolved, exuding an eerie and sinister aura.
Song Wen opened his mouth and spat out the Blood Sea Seal, which flew into the air and landed within the vortex at the formation's center.
The moment the Blood Sea Seal entered the formation, it immediately resonated with it. The seal trembled slightly, emitting a low hum.
Song Wen formed hand seals and activated the formation.
The entire formation blazed with blood light, while the blood-colored vortex spun faster and faster.
Streams of pure blood essence surged out of the formation, flowing like trickling rivulets into the Blood Sea Seal.
Vein-like patterns emerged across the seal's surface, crimson as though ready to drip with blood.
As the blood essence poured in, the bloody patterns began to writhe like living things, as if tiny insects were winding and crawling over the seal's surface.
The pressure emanating from the Blood Sea Seal gradually grew stronger, while the entire formation slowly dimmed.
Clearly, the sacrificial refinement formation Song Wen had set up had succeeded.
Once the blood essence contained within the formation was exhausted, this refinement would come to an end.
But that was clearly not enough to satisfy Song Wen.
Essence blood continued to flow from between his brows and fly into the sacrificial refinement formation.
In an instant, the somewhat dim formation patterns lit up again. Blood-colored light surged like a tide, and the blood essence within the formation became abundant once more.
The Blood Sea Seal was like a