In a normal combat state, he wouldn't bring much stimulation to the environment of this world, but in overly intense battles, the environment would be affected, giving rise to those Mental Aberration creatures that possess extremely weak souls yet very strong powers.
However, the fragile soul of such beings does not mean they are easy to kill; the Mental Aberration creatures' outer layer of power in itself is a special protection, strong enough to withstand most attacks targeting the soul.
"I hope someday I can summon a bunch of beautiful and powerful Heroic Spirits or Evil Spirit sisters."
"...With all due respect, boss."
"Speak."
"If it really develops to that point, during a tough fight, are you willing to let them go into battle and die willingly?"
