None of them, it will be a custom Rogue.

I usually play a character loosely based on the Corwin main character in the Amber series. Fighter class in D&D might be closer, but Corwin wasn't really a heavy tank. A Rogue in light armor with a rapier feels better.

Astarion would be the closest Origin character to that template, but I don't want to be locked into his scripted story line from what I can see of it so far. I did play the Ifan Origin character in DoS2, but his quest and story was a minimal intrusion on role-playing in that game. It looks like the companion issues are written with a heavier hand here in BG3.