Even a rank 4 giant that gets hit by an attack with a power of 7,815 units would die in one blow. So a rank 3 cultivator like Greg hiding within the cockpit of the mech would fare worse if the attack had struck him. Not only would he have died, but even his corpse would be scattered and mangled.
Even though the first attack failed to kill Greg, Loki still had the absorbed second attack to enhance his power. So he was able to give it another shot by jumping towards the silver mech.
The mech tried to protect itself by blocking with its large shield. But the sword was able to cut through the shield and the arm holding it.
At the end of the day, the mech was able to escape and create even more distance between them. But what saved the mech wasn't the strength of the shield or the strength of the arm holding the shield. It was the length of the arms of the mech that saved the mech.
