I wouldn't all what Vieze got a redemption arc, a moment of clarity leading to him accepting punishment maybe.
It is really hard to do that since keeping him alive will mean Perez will have someone claim him as the rightful heir to the throne. Ending him is the best choice for all
He genuinely wanted to kill Perez, for that alone he deserves to face what he wanted to act on others. Not to mention his inferiority complex (both raised this way & inherited from the dumb emperor)
Astana really is pitiful. Raised by horrible people in a way that made him rotten but if anyone deserved a redemption arc it should be him not veize. I hope perez doesn't go too hard on him cos it'll be hard to watch.