Darth Nihilus runs the gauntlet

40 meters starting distance, full knowledge and recovery

1. Githany
2. Act I HoT
3. Darth Malgus
4. Ulic
5. Mando Wars Revan
6. Darth Revan
7. SF Malak
8. KotOR Revan
9. Revan Reborn
10. SoR Revan
11. SWTOR Vitiate
12. RotJ Sidious
13. DE Sidious
14. SSJ Luke Skywalker
15. FotJ Abeloth
16. The Daughter

Stops at revan reborn

If Ulic can counter his drain, stops at 4. If not loses to 8-9.

4 or 5.

Dies at 11 or 12.

Dies somewhere from 8-10.

Clears

5. Mando Wars Revan

This is the earliest that could realistically counter his drain. Mando Wars Revan doesn't have the feats and overall resume to win though.

6. Darth Revan

Darth Revan would be familiar with drain, but I don't think he has comparable feats.

7. SF Malak

I could see Malak winning this if he can close the distance, as the Star Forge may be able to counter the drain. I don't think he can deal with Nihilus's absurd raw power though.

8. KotOR Revan
9. Revan Reborn
10. SoR Revan

At some point here, I think Revan gets masterful and close enough to Vitiate to defeat Nihilus. It's a bit of a guess though.

11. SWTOR Vitiate
12. RotJ Sidious

Nihilus definitely falls around here.