Beldorion

Holy Shit, Beldorion was a loser and a jedi, he was arguably the BIGGEST LOSER OF THEM ALL as he never made it past the rank of Knight.

As a Jedi
not much is known about his childhood, but when he became a Jedi at age 18, he had daily relations and got drunk, he was trained by a cocaine-abusing Yoda.

As a Sith
he became a sith as he got tired of his boring jedi routine so he became a sith and done a load of cool stuff, hell, he let us down.

Redeemed
he was redeemed by Leia Organa Solo but at the last minute he was killed by Darth Voldemort.