In order to get good/bad ending with a succubus you need to choose right answers in the dialogues with them. It's essentially a dialogue tree. Sometimes requests are interjected but they don't appear to matter.

There's already a tree guide from a presumably Chinese user but it's somewhat confusing. I'm trying to make a better version. Here you have a starting phrase for each part of the conversation and spelled out answers with arrows directing the dialogue flow.

The dialogue starts from one of A1-A3 nodes. Usually A1 if it's the first time talking with that type of succubus and A3 for the following.

It's a lot of work so mistakes are inevitable.