Because souta knows that defeating No God emperor without the blood card is possible, so why would he use his one time use trump card that lets him become low rank God level for an hour just to defeat a 5-6 shackles level No God emperor

A casual attack from a fifth evolution monster is probably enough to destroy our current earth dozens of times over( since our world is much weaker than even low level world), considering earth's size 70 floor building is too small

At least the author should tell how much boost souta got from the souls

zero probably got promised by laxmus to revive the fallen

ordinary people have to fear hotshots but hotshots have to fear Lu Xiaoran