To spare Undyne, the protagonist must deflect her spears while in Green Mode and flee from her while in Red Mode (they cannot escape in Green Mode), gradually making their way through the cave she was guarding.
How do you beat Undyne in Undertale pacifist?
To spare Undyne, you need to survive her waves of attacks until she changes your heart back to red and throw a spear at you. Run during this turn. When you get on the overworld map, Undyne will be stunned for a moment. Use this to run upwards.
How do you befriend Undyne?
Befriending UndynePointing the spear at Undyne while she demands them to choose a drink causes her to ask if the protagonist is flirting with her. Selecting the Sword when she demands them to choose a drink causes her to comment that she would gladly fill the protagonist with swords if they were not her house guest.
Is Sans stronger than Undyne?
Undyne The Undying is stronger than any monster in genocide, even sans.