The top master in Cultivation world is a damn single and has been single for thousands years. Not mention of girlfriend, not even a sister. That is the reason why he saves his enemy's sister. Step 1: Save her and bring her up Step 2: Teach her cultivation skills to protect herself and insist to tell her bedtime stories to creat himself a great image Step 3: Send her jewels that most women like to dress her up That is what a perfect brother should do. Sister, "What the hell does this pervert who pulls me up every night to tell me ghost-like stories want to do?"