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A pair of Roenall Guard's will accompany Lord Roenall when he comes to the de'Arnise Keep to demand that Gorion's Ward give up the castle to him, if you have met the requirements to take on the keep as a Stronghold.

If you deny Lord Roenall an audience, then the fighter will appear instead and deliver a message.

My lord has bade me to come within and give you this message, since you are arrogant enough to refuse him at the door.
He says that he will not allow you to keep playing at being the <Lady/Lord> of this keep which is rightfully his. Lady Nalia had no legal right to give Roenall land to someone else.
And since you will not be reasonable about this, Lord Roenall will return... with an army. That is all.

Later when Lord Roenall attempts to take the keep by force, three of the guards (two fighters and a mage), along with three soldiers, will compries the troops the Lord has brought with him to the battle.