Okay then do you want the answer? Here is another hint-this character is super hard to think of. He appeared in both legends and canon and was written by Timothy Zahn.

Is it Rukh?

No

He is a Chiss.

A chiss in both legends and canon who has not appeared in a live action, which obviously rules out Thrawn, Humm not my area.

Are they a part one of the chiss ruling families

Yes.

Is the family mitth

Yes

Is it Thurfian