No, see, prez, sorry doesn't cut it. Not that you are apologizing, even now.
You violated two things. The first is your own reputation. Why should anybody trust you? I'm not going to trust TNP2 anymore, who knows what you'll stuff in there. You can't even bring yourself to promise not to add malicious code anymore, just "not in Tart's mods". What happens next time you argue with someone online? You add code that harms users over your own agenda? People's trust for you will be in the gutter, and can you even blame them?
The second thing is Tart's intentions. He didn't make Diable free for anybody to update for it to be made a tool in modding vendettas. He did this so that the community could have fun. Playing Diable. You, in accepting the duty of updating this mod, are the steward of this mod, not its owner. The community and Tart are implicitly trusting you with this duty. What did you do? Spit on it.