Secret Bosses and the ending (spoilers)

[Warchon]

Hopefully a simple question, but I've had no luck googling these possible edge case scenarios. Are any of these possible?

GENOCIDE (Kill Sans and get a neutral ending?)
Can you go back after killing Sans and fight Glyde or Temmie, then spare them to abort genocide?

GENOCIDE (Sans remembers you killing him, then doesn't fight?)
After killing Sans, can you reload your save (so that he is not dead) and then go back and spare Glyde or Temmie?
Seems like something that might get a special comment out of him. :)

PACIFIST (Sans loves you, you're still a ♥♥♥♥)
After being judged by Sans, can you go back, kill Glyde, Temmie, So Sorry, or a random Core encounter and change your ending?

ABORTED PACIFIST (Sans wonders why you changed your mind so late)
After being judged as a pacifist, if you reload to pre-judgement and kill something, does Sans comment on the late change of heart?

[(Edgy) Asriel Dreemurr]

For the first two, sparing monsters doesn't actually prevent getting genocide, except for set encounters like Snowdrake and Shyren which can't be skipped without hacking. Once you kill Mettaton NEO with genocide intact, the only way to get out of a genocide route is by resetting.

Next one, those specific monsters you listed can no longer be encountered once you've beaten Mettaton EX, as all random encounters stop as does So Sorry. Glyde actually stops spawning after beating Papyrus or if you have a certain number of kills. However, if you opened the way to Mettaton in the Core via the puzzle, there are three encounters set on the "warrior" path, and these I believe can still be activated after being judged by Sans.

Last one, if you use the method mentioned above you can test this. I suspect since it's kind of a bug that you can do this anyway, he would just comment on whatever LV you have as he would normally, heck it may even crash the game. You would have to test it to see.

[Warchon]

I can now verify this.
Sparing a Random Encounter monster doesn't abort Genocide, as mentioned by Edgy.
Killing a monster after receiving Pacifist judgement does abort Pacifist. (Sans does not come back but you'll fight Asgore and Flowey and get the standard ending)
I didn't test reset-rejudge, but I doubt anything would happen there either.
Ah well, it was worth a shot.

[(Edgy) Asriel Dreemurr]

Originally posted by Warchon:

I can now verify this.
Sparing a Random Encounter monster doesn't abort Genocide, as mentioned by Edgy.
Killing a monster after receiving Pacifist judgement does abort Pacifist. (Sans does not come back but you'll fight Asgore and Flowey and get the standard ending)
I didn't test reset-rejudge, but I doubt anything would happen there either.
Ah well, it was worth a shot.

try the method I mentioned, only after beating photoshop Flowey, or perhaps even after completing the Alphys date.