1) I am Lord Vexas, one of the Empire's foremost SIth Juggernauts and a prodigy of Soresu, as well as a master of combative telekinesis. While technically a Darth, I have never been given a name (such as Marr or Arho) to go with it, so I go by Lord Vexas for now. Not only this, but I am the Emperor's Wrath - I am feared and undefeated in combat. I can open a lot of doors for you within the Empire. I wish to be a part of Czerka as you are a neutral party; you are capable of creating great change in the Galaxy, and I wish to be a part of it. I would be an invaluable military advisor, as well as an enforcer or even ambassador - my reputation has proceeded me before, and will again.
2) a) I struck down my master, Darth Baras, who had several times made attempts on my life by proxy, in front of the Dark Council, and was formally recognised as both a Darth and the Emperor's Wrath.
b) I emerged victorious and vindicated from the tortures of the Korriban academy, having crushed my enemies underfoot.
c) I met with and duelled Revan, a man who was and still is a personal inspiration.
3) I achieved these feats using unparalleled willpower and my mastery of the Force.
4) I have a strong sense of honour. My only absolute loyalty is to the Emperor and my crew, although that is not final, and I am open to further commitment. I can, however, overlook honour if it serves my purposes.
5) Using a lightsaber, presumably