How to get Neil's endings
There are 4 main types of choices in the route:
- Vampire training
- Romance
- Morality
- Other vampires
If you followed all the published guides, you will get the villain ending and all the illustrations. This means picking all the choices pro romance, successful vampire training, twisted morals (kill humans and follow the idea that "only power and freedom matter" etc), and be ready to shit talk the other vampires and accept to get rid of them whenever asked.
If you want the neutral ending, do the complete opposite of what’s in the guides.
If you want the positive ending you have to do a mix of negative and neutral, this means that you have to pick all the romantic and vampire training choices like in the guide. Then, keep your humanity, meaning don't kill and defend humans whenever you have the chance. When you talk to or about the other vampires keep things mostly neutral, follow the guide but whenever asked if you want to get rid of them say no, that they are your family etc. Keep mostly neutral about them when talking to Neil and avoid murder. The A/B choice at the end of chapter 9 is important, choose peace not freedom. You will still be able to get all the illustrations (if you don't it means that you've picked a few too many wrong choices and should stick a bit more to the guides, in theory).
If you have followed the guides but want the positive ending but also don't want to replay from the beginning, I think you can obtain the good ending by doing the opposite of what's in the guides from around chapter 7, but this means that you will lose illustrations 7,8 and 9 and the story will make less sense.