One thing I will say about the speech: We don't make any mention of the fact that Aerys was our friend. If anything, it kind of seems like we're coming across as a callous asshole.
Aerys' death might be what Steffon's sadness and guilt are about. Like he's feeling like he could have done something to stop it (even if he couldn't). No matter what differences we have with Steffon, Aerys was still friends with both of us.
Maybe he's wrestling with the idea that he'll need to become king because it will mean being able to do something about what happened, but he also knows that he wouldn't make the best peacetime king.
So, maybe something like this? Not really any mention of steffon at all but this is more making a case
for Rhaella (And House Targaryen cause nobles just love them some continuity.) rather than
against Steffon. Which is probably for the best in case Steffon wins. Don't wanna burn that bridge if we can help it.
(Edit: Also damn, did not realize this would be 666 words exactly...that's not ominous at all...)
[X] The King's Sister Speech
"Lords and Ladies of the Seven Kingdoms! I am Ser Arstan Arryn, Heir to the Eyrie and sundry other things that have little bearing on what I must say. And what I must say is
look! "(Gestures to Rhaella)
"What is it you see? A Princess? The Blood of Old Valyria? A woman? She is all those things, aye, but I know her most as my Lady Wife as all of you no doubt plainly know. Thus, it is my duty as her husband to defend her rights as the last Targaryen. This I do gladly and not for want of crown nor glory, I do this because it is right and good that I do so. Because it is also a duty to my friend and brother in all but blood, King Aerys was the Blood of the Dragon through and through this I know. His reign was not long, aye, yet was it not sweeter than most all before him? Did not the lands of the Reach know his magnanimity and mercy time and again? Are not the Westerlands reminded of his loyalty to those who are true to their lords? Do not the people of Dorne remember his desire for their justice? Have the Ironborn forgotten his largess that rivaled a kingdom? I know the Riverlands and North did not have great deeds done for them yet it was early days and I do remember the patience my good-brother showed when I was gifted a crown. I must humbly ask you consider that, my Lords.
King Aerys the Second was on his path towards greatness and in that final destination he has great company. Aegon the Conqueror, Jaehaerys the Conciliator, Baelor the Blessed, Daeron the Good and Aegon the Unlikely are the greatest men to bear a crown the House of Targaryen has ever produced as no doubt your maesters have taught you. Yet, did not most of them have a Queen at his side to aid in his glories and did not some lesser kings have Queens to lessen their harms? The Two Dragonesses of the Conqueror Rhaenys and Visenya, Alyssanne the Good Queen, Pious Naerys and even the Queen Who Never Was, Rhaenys, daughter of Prince Aemon. And of course our Queen Joanna, though not a dragon who among us would dispute her place among those worthies?
House Targaryen has produced the finest rulers Westeros has ever known, we have known more peace and plenty under it than ever there was under the Seven Kingdoms when apart. To abandon it's memory now, such could only be called ingratitude, surely? Again and again I have asked you remember but now I ask once more,
look." (Gestures again to Rhaella)
"Many would say a woman too weak to bear a crown yet how many of you could trek through mountains and rivers while two lives grow within you? While the grief of a lost brother, nephew and niece gnaws at you? While the weight of a dynasty of over two hundred years and over a million souls weighs upon you? Look where she is now and ask if she is a weak woman. I could regale with laws and precedence about sisters inheriting after brothers yet House Targaryen has always been an exceptional thing. Yet should not it's women be equally exceptional?
Think of your mothers and sisters and wives who have suffered and sacrificed to ensure the prosperity of your Houses. Think of your daughters who would do so yet again for your neighbors and friends. Now think of what a Queen would do for a Realm. None should fear nor dread it for this Queen will be
strong. For she was strong while her brother and husband warred, for she was strong while ruling the Mountains and Vale in our place, and she will be strong upon the Iron Throne, this none should doubt! Do not forget that she is a dragon still and she-dragon's are as fierce as their brothers!"
