Darth Krayt vs The Outlander

The Outlander. Regardless of whether he's more powerful than Unchained Vaylin he still grew massively over the course of KOTET as can be seen by him losing solidly to Chained Vaylin and then being above Unchained Vaylin (whether it's through superior combat skill or superior power does not doesn't matter) by the end of it. This basically means he's scales massively beyond his Act 3 self (including KOTFE growth here as well) which is more than enough to put him beyond Reborn Krayt.