The villain is utterly immoral; with a dragon charging right in his face, how could he possibly lose

Anyone who's ever been bound to a system knows that calling someone "godfather" is only natural. Gu Qing is reincarnated into a fantasy world, becoming the brother-in-law of the protagonist Lin Chen. At the same time, he's bound to a super anti-armor system, reflecting all damage. The prodigy protagonist declares, "With one sword, I open the gates of heaven; I am invincible among mortals. If I don't fight heaven, who will I fight?" The arrogant protagonist declares, "If heaven tries to stop me, I will slay it." The heroine protagonist says, "What goddesses, saints, or demonesses? They're only fit to be my maids." The system protagonist declares, "I will cleave eternity with one sword." Gu Qing is speechless. "I have a godfather by my side; how should I deal with this?"