Time travel, system, both are great... the only problem is...

This system is way too late! I've only arrived after my second time traveling through time!

The protagonist fights for his own interests; he's not mindless, and has a dark side. Enter at your own risk if you dislike this. The female lead's role depends on the situation. The protagonist is a transmigrator from the Type-Moon world, a second-time transmigrator and full-time mage. He's a clock tower magician; if you dislike this, please skip.