Not sure how well this translates to another countries laws.
From my limited knowledge on the lip and mofu stuff. Lip gave you permission to use these characters and ideas. If you have that in writing and it's dated like a text message or email legally there is not a thing lip can do.
It can also be argued that you are the original creator by giving the idea a medium to exist before anyone else.
You do not need to remove anti aliasing that's a standard practice in video game development.
You do not need to remove changing the body shape because mofo your the original owner of that concept from your previous game.
You do not need to remove teleport functions. Because that's a standard practice in videogames.
I understand it's easier to just remove the characters and move on and I would probably do the same to make the headache go away. However and again limited knowledge on lip but you know the details.
It sounds to me that lip will never go away and will always bring you drama no matter what you do.
Keep up the good work mofu. Don't allow one overbearing "fan" dictate your game.