The Hero is called Sebastian Parnell. He is a legitimacy group, so you can unlock him randomly when conquering planets as an Imperial Warlord Faction.

Thanks for the name, but I have like eight or so legitimacy groups in my current game. But he is not there, so it is completely random? That sucks, was hoping to know which group he belongs too. Thanks again for the reply.

His Group is called the Si'luume group or similar and only includes him. It is fully random. You can check in the political tab if another faction got him first, if not, you might yet unlock him.

Thanks again, your more helpful than most people on steam.

If you want helpful people, join Corey's Discord server. People there will explain and give you tips about everything (and will argue about everything, but that's Star Wars nerds for you).