Please note that this is just a concept and this is not real.

If I were Sarah, it would be hard for me just to pick one Alternate timeline/universe for the final area. But "Help from the Void" is a three in one package with Rejuvenation/Nihilism, Disbelief, and Last Breath. However you can only get this encounter from genocide. (I mean it's obvious, right?) And if you're wonder how Undyne died, Waterfall is the fourth area in the genocide route and that route only.

Deltatraveler by @RynoGG

Help from the Void by Harmony.

H.F.T.V. Battle animation by @VennisOfficial

Rejuvenation/Nihilism by @Wrenblu

Disbelief by Liquid Mog and Samuel Wolfang.

Diselief owned by @flamesatgames

Sprite by @nekma

Last Breath by ZerJox.

Sprite made by @AleAtorio3Dw (I think.)

Undyne the Undying sprite by Toby fox.

Happy second anniversary Deltatraveler.