A run where we have to do the 3 principal ending : -one of the neutral -Pacifist -génocide

I think that would literally just be Soullest Pacifist, which is already a misc. category.

the Soullest Pacifist?

"Start with a 0-reset fresh game. Complete the Genocide route, followed by the Pacifist route to achieve the Soulless Pacifist Ending. This includes the 10 minute wait after Genocide" (rules of the soullest Pacifist)

I didn't see the neutral ending

The neutral ending would be completed as a part of the True Pacifist ending. I don't really see a need for a separate category with a completely separate neutral ending; it'd just be redundant, since you already play through the entirety of a neutral ending in True Pacifist.

But, I think do the 3 principal Ending in one run was a great idea

but you do a neutral run in souless pacifist because you need a neutral run to do true pacifist

you do a full genocide run, then you give up your soul and reset. You kill flowey as part of a True pacifist run's neutral portion. then you proceed to complete true pacifist.

When asking for a new category, one of the primary questions one should ask themselves is "What does this category offer?"

You're asking for a category that completes all 3 main endings, which already exists in the form of Soulless Pacifist, but you then claim that's not what you want, you want 3 separate playthroughs: One of Genocide, one of Neutral, and one more of True Pacifist.

So I direct that question to you: What does that category idea offer?? It's literally just Soulless TPE with another Neutral playthrough stapled onto it for no particular reason other than just 'because'.

This has no reason to exist.

All endings is TPE, genocide, and all main variants of neutral. It should specify in the rules for all endings.