Considering the other Fausts keep warning Mao Faust to not trust or follow Lord Lu, but her remaining obstinate about it, do you think he has more in mind than just ruling over the place himself? I don't see how the trauma would make him desire that, if anything, I think that ruling is just an excuse to further escalate, or control the suffering himself.
He wants to punish the entire place for never having reached out to him and hugged him when he was hurting, and by becoming the sole lord, he can just make the place run for as long as possible, while maintaining the misery so he can maintain that punishment for as long as possible.