You Suffer, I Reap the Rewards: The System Chimes, and I Win by Doing Nothing

Why should the System make the Host do the missions personally? That's simply unforgivable! Dropped into a fantasy world, he binds himself to a God-Tier Power-Leveling System. The Host is responsible for triggering missions. The System randomly finds someone to power-level and complete them. The mission rewards? They naturally go to the Host! You did the power-leveling, and now you want the rewards too? You can't have it all, you know?!!