The blood-colored sand grains all originated from his own blood.
This was the Origin Blood of the Sparrow Wolf God; even though it had dried up and turned to sand, it could still be used, indicating that when his blood wasn't dried, he could also use his Divine Blood for all kinds of slaughter!
The speed at which those blood-colored sand grains transformed was incredibly fast, behaving not like lifeless matter, but more like living entities, similar to those terrifying Mosquito Dragons Minglang had encountered at North Utmost Ridge.
The Sparrow Wolf God turned his fist into a palm, and all the blood-colored sand grains instantly morphed into a massive, cloud-sized, blood-colored palm, slapping towards Zhu Minglang like swatting a fly.
Zhu Minglang raised his sword to meet the attack, sweeping a large swath of Sword Qi in front of him; the Sword Qi formed a crescent barrier, blocking the cloud-sized, blood-colored sand palm.