The character should follow lore as to that of Disco.
Anything you put in the story should be what could happen in Sirius.
Other than that really... its up to you what to create.
Its a character you make to be placed in the setting of Sirius. You decide his attitude, his/her allegiance, his/her background, way he/she thinks, etc.
I cover a few ways you can make a character here, if you want. http://www.youtube.com/watch?v=_SzOu_5ke-Q
You don't have to do the whole ironman mode thing or have a closed economy, but the sites I link to are a good source of random inspiration.
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PSA: If you have been having stutter/FPS lag on Disco where it does not run as smoothly as other games, please look at the fix here: https://discoverygc.com/forums/showthrea...pid2306502
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The way i do/did it is i was in a faction, needed a character, and looked up some of my favorite actors as attitude and look. From there I just RPed with people and developed my character and his/her story.