Alek vs Darth Bandon

Mandalorian Wars Alek
Prime Bandon

Sabers 
Force 
All out

Location: Tie fighter factory over Nar Shaddaa

Bandon force pushes him onto a console which then detonates and kills Alek

Bandon. He's implied to be superior to Darth Sion (due to Bandon being said to only be second to Malak within the Sith Empire, and Sion having been part of that same Sith Empire). He's also never met his equal in combat until facing Revan. He's just got better accolades than anything Alek has going for him.

@Underachiever599 I find the implication of Bandon being>Sion very dubious to be honest considering Darth Sion didn't exist as a character until KOTOR 2.
Even if this was the case in universe, it's highly likely Sion surpassed him anyway as of KOTOR 2 as he had five years to grow after the death of Malak's sith empire

Bandon is above kotor Revan and has never met a worthy opponent including his master Darth Malak, he ragdolls pre prime Malak fodder