What Su Zhou wanted to cultivate was, naturally, the same kind of Divine Technique the Great Roc Golden-winged Bird possessed—one that allowed it to switch to its beast form and guarantee its survival even after its human form had its head blown off.
When Garuda was hit in the head by a shot from Bai Canglang's Extraordinary Sniper, Su Zhou had activated the Pentagram to enhance his Soul and enter Bullet Time. He clearly saw how the bullet shattered the girl's skull, scrambling the brains and blood within. Logically speaking, it should have been a fatal blow. At the very least, Su Zhou felt that if he took a hit like that, he'd be at least half-dead.
As for why only half-dead, it was because he still wasn't sure how much damage it would take to actually kill him. As of yet, there was no one in this world who could push him to that point.
