Okay, so. I'm... fairly close to finishing my first run of the game, which has been a pacifist run. No kills whatsoever, and all that. I was wondering - would I be able to tackle subsequent runs like this?

• Pacifist run (befriend everyone except Alphys, fight spare Flowey)
• Reset into Genocide run that gets dunked on by Sans
• Reset into second pacifist run, this time get the True pacifist ending
• NEVER EVER RESET THE GAME SO EVERYONE CAN BE HAPPY

Basically: do I have to do the True Pacifist ending on that very first run? As I understand it, since it's my first run of the game I'll get the neutral ending and Flowey will be all, "hey go befriend Alphys some more", but do I have to go do that on that run or can I just do it later?

It's just that, even if I'm not going to go all the way through with the genocide playthrough, I'd still feel really, really bad resetting a nice and happy true pacifist run to murder almost everybody and then try and give them their happy ending again. (I am far too attached to these characters, I know.)