Rarth Devan looks vaguely familiar to Darth Revan...
Rarth Devan is the current Chief Safety Inspector for The League and the one-time bunkmate of Trask Ulgo on the Endar Spire. He is a bit absentminded, and he can lose his memory occasionally.
His sudden appearance immediately after the disappearance of Darth Revan is simply a coincidence, nothing suspicious here...
Despite apparently serving alongside Trask on the Endar Spire for two years, Rarth has never met him in person. Unbenownst to him, Trask has been secretly playing a massive-scale game of Hide and Ulgo Seek, with Devan being 'it' 100% of the game. He had never caught Trask once up until the attack on the Endar Spire, which was orchestrated by Trask anyway to give him an excuse to reveal himself to Devan, save the day, and apparently die. But we all know that didn't happen...
After leaving Endar Spire, Devan set out to perform his life's ambition: writing a Travel Guide ...
He ended up going on this massive journey to become a Jedi, only to then accidently kill Darth Malak during a circus performance and be heralded as a hero. Trask Ulgo watched from the shadows, his plan complete. But he let Rarth take all the glory because, y'know, he's Trask. Rarth Devan thn went out on a scouting mission for the League, and left the Galaxy onboard the Ebon Hawk, to explore Galaxies outside his own, the Force Galaxy. He now lives in the League Galaxy and has taken up the role of chief safety inspector.