I Serve My Patriarch by the Merit of My Own Skills

Tang Yu transmigrated. This adorable cultivation world, where humans and demons coexist in harmony, is so lovable. Even with a good-for-nothing constitution, he's perfectly content: he's reached Foundation Establishment and can live for two hundred years. (Puts hands on hips.) What? They want him to serve the Patriarch? Fine, he can consider it a way of respecting his elders. Maybe he can even use the chance to cling to a powerful patron! After the war between the Dao and the Demonic Path, the demon clan's Patriarch, Shentu Kun, was left with a damaged soul and became a ticking time bomb. This low-level outer-sect disciple can actually... calm him down? A quick divination reveals... such a coincidence? Well, he won't hold back, then. ...What's with this guy? Making all those rare flowers and herbs into food is one thing, but what happened to cleansing his meridians and strengthening his body? What happened to advancing his cultivation? At first, the sect members say: Tang Yu clings to the Patriarch's leg. How shameless! Tang Yu puts his hands on his hips: I earned the right to cling to him. If anyone disagrees, come and try me. Then the sect members say: Oh no, the Patriarch is on a rampage again! Quick, throw Tang Yu at him! Tang Yu, the instant stabilizer: ... A good-for-nothing gluttonous bottom who loves to complain VS a violent, scheming top who frets every day over how to help his husband level up Premise: