Travels in Another World: the Undead Brigade

"Young man, do you want power? Power enough to slaughter a city and destroy a country, power enough to shake the world!" "So, what's the price?" "What price?" "Um, for example, will you seize my body? Or complete some evil plan?" "... Have you read too many novels?" When Mo Shuyu accidentally traveled to this world, he received an extremely powerful force, but the other party's only request was to let him travel?