Going out of their way to attack and antagonise one of the most powerful Dukes in Kindara while still a new noble and then throwing a hissy fit when he didn't get a lordship he wanted, attacking another Duke and the Ruler in the process, seem like perfectly good reasons to IC exclude someone from power. There doesn't have to be anything OOC about it. Your character acted like a spoiled brat and is now reaping the consequences.
It reminds me of the time when a new Arcaean noble, upon being told that rape and pillage was expressly outlawed and one of the worst crimes in the realm, immediately went to a neighbouring peaceful realm and had his troops rape and murder. Upon being punished, he demanded the Ruler apologise to him and then was seemingly shocked when he was no longer welcome in the realm.
And he is still in your realm? I am surprised by Kindaran generosity.
