In My Second Playthrough, I Can Only Spend My Life

So, I've transmigrated to another world.

"Great. That means I'm the protagonist."

And become a general's son.

"Because I'm Xilin Luomen!"

This world has already been destroyed once.

"Listen up, I'll protect everything in this world!"

I've been bound to a System.

"Restoring the System to glory is our duty!"

Using the System costs lifespan.

"Huh?!"

Xilin: "Can I return it? I don't want the System anymore. Or, you could let me pay with money instead."

System: [Host, don't worry about it. Besides, you still have your life, don't you?]

"Staying alive counts as a win!"