Questions in UNDERTALE

This might be a really stupid Undertale question, but how do you fight Sans?

I did the Genocide run and he didn't fight me. I'm so confused.

https://gamejolt.com/p/killertale-nico-y-cata-con-estadisticas-v…

Why don't i make a fan game of undertale.

If this gets over 60% yes then im making it

I did it i drew it sorry it took long buts its here. So should i draw more of these things i mean like alot of them tell me if i sould

In your opinion, which is better?

https://gamejolt.com/p/perdon-por-la-demora-estuve-trabajndo-en-…

https://gamejolt.com/p/english-intercambiar-nico-y-cata-con-esta…

https://gamejolt.com/p/english-swap-nico-and-cata-wiht-stadistic…