Panel 12 adds to my feeling that Tarkin will get killed by Xykon in the most undramatic, ironic way, without a big speech and such. And Xykon will say sth like "who was that dude?"
Anyone else things Tarkin will end that way, too?
I do hope he lives long enough to realize he was wrong, but is incapable of fixing the situation. He is incapable of regret. Anything else would be too perfunctory.