"100 War Chariots" 

Hydra's grim reaper…this one was a curse without a medium. It wasn't a real living being grim reaper. 

A curse would only faithfully carry out its function until the mission was accomplished. 

The cursed Valkyries...even if they could protect their souls, they would discover that their soul flame slowly becomes dim, as if about to go out. 

Then, in the next few seconds, the soul flame would be extinguished entirely. 

When this happened, the Valkyries would definitely die because they were beings with souls, unlike some strange creatures that didn't have souls. 

After all, to have high intelligence, one would still need a soul. 

And so, the Valkyries slashed the fog grim reapers with their void slayer technique one by one, desperate to kill these reapers. 

SLASH! SLASH! SLASH! 

Unfortunately, the fog was only scattered for a few seconds.

Then, the fog would reassemble, forming a new grim reaper that was unscathed.