Good, by any means nessecary? Alignment question.

[LudicSavant]

As title.
To clarify, a person who is so obsessed with Good that they are willing to force anyone and everything to be Good. By any means necessary. Whether their acts are selfless or selfish, nice or horrifying. What would their actual alignment be? On the one hand, 'Good'... yet, on the other hand, atrocities are just evil...
...so basically an insane Celestial, I guess?

If your question is "what Alignment will they be" the answer is "it's totally arbitrary and DM-dependent, because Alignment isn't defined consistently enough for there to actually be a correct answer. You can make the person's alignment be whatever you feel like and nobody could actually correct you."

If your question is what we think about the morality of this character's actions, that's entirely different.