A Necromancer's Wish for a Peaceful Life

Only after our protagonist stabbed the blonde girl with twin tails who appeared before him straight through did he realize he'd apparently killed the wrong person.

After thinking for a few seconds, he made his decision.

"Well, it's come to this. Might as well do it while she's still warm."

And so Eriri was turned into an undead, and in tears, helped him clean up the messes plaguing the world.

☆

The protagonist starts out aligned with lawful evil. If you can't handle that, please steer clear.