This is such a fun idea to play with. AU where Rhaenys married Viserys and Corlys married Aemma, but Rhaenys cheats on Viserys with Corlys. As a result, some of Rhaeny’s kids are actually Corlys’s but Viserys treats them all like his own. When Corlys fails to have any living children with Aemma (miscarriages, stillbirths) he wants to legitimize his bastards with Rhaenys as Velaryons but Viserys doesn’t want to let him. Meanwhile Daemon decides to push his case as the only legitimate heir and marries Rhaenyra (who is Viserys’s legitimate daughter with Rhaenys) against her parents’ wishes. Daemon makes an alliance with Corlys by promising him he can legitimize those of Rhaeny’s kids he believes are his in exchange for backing him. Meanwhile Rhaenys gathers support for her oldest son (who she of course named Aegon) who is actually Corlys’s kid but has been raised believing he is Viserys’s. Most of Westeros would rather have the more even-tempered Aegon for king than the Lord of Flea Bottom and Maegor with Tits. Their marriage is also seen as illegitimate by the Faith (Rhea managed to avoid the divorce rock) so the more religious lords back Rhaenys. A dance of the dragons ensues.

Viserys explaining his reasoning to Corlys: “I had a silver mare once that mated with a silver stallion. Guess what color the foal came out… palomino.” XD

rhaenysviserys failmarriage is sooo fun <3

putting aemma and corlys together is interesting i hadnt thought of doing that before…but it works

i think viserys would know that some of his kids arent ‘his’ but refuses to fully admit it to even himself. first of all because he would defend rhaenys before he defends himself and second because rhaenys has him broken so well he mostly just does what she tells him, if she says these kids are his then theyre his. secret third reason: he still likes to pretend she loves him back

rhaenys has been having the affair with corlys because hes the one she really wanted to marry, but if she wanted to keep her claim to the throne she needed to marry viserys. corlys was supposed to be her comfort in her pseudo-forced marriage and now hes betrayed her. trying to steal her throne and her children.

daemon feeling rejected and abandoned by viserys ‘choosing’ rhaenys over him, hearing about corlys claiming some of rhaenys kids as his own, decides to help spread a rumor that ALL of rhaenys kids are bastards. conveniently making him viserys only legitimate heir again.

the dance always wins ☝️

How different the events would have been if viserys did made aegon 2 his heir? Would daemon have seduced Rhaenyra then and what's viserys reaction would have been? Whom viserys would have wanted her to marry in this case daemon or laenor or someone else Also is it possible that a dance would take place in this case too. Maybe with daemon marrying rhaenyra and using her being firstborn as excuse and with velaryons and possibly north at his side and daemon striking first.

Hi there Anon! And per my usual XD sorry for this huge delay!

So, the question is quite complex so I will do my best to answer this one. Let's begin with the easiest part of it all, of "Would daemon have seduced Rhaenyra then and what's viserys reaction would have been?"

The answer is absolutely yes without a shadow of a doubt and for several reason:

1- Even if not the heir, had Rhaenyra been not remained the heir in this scenario, should her half-brothers die, either her or Daemon would come next. Daemon wanting to tie their claim as one would make a LOT of sense for both, and he absolutely was the kind of calculating and shrewd man who could see this. Again, should Viserys's sons die, instead of a debate of "Who comes next? The king's brother or his daughter?" That question wouldn't exist both would. 

2- From a Targaryen stand-point, with Daemon having no sister, a niece would be the second best thing. And Rhaenyra, like himself, was a dragonrider. We also know (because George didn't do a good job on a lot but he did on this) that Daemon really wanted a son, and by a Targaryen stand-point, again, Rhaenyra would be the best choice for baby mama.

3- Even if she was not helping his ambitions, Rhaenyra was in Daemon's own words "the most beautiful maid in all of the Seven Kingdoms" (sorry if the exact wording is escaping me but I am too lazy to go and grab my copy of Fire and Blood right now hehe XD). She was also the Realm's Delight and the prize everything straight enough and that had a 🐔 was lusting after. In 111 AC to top her looks, Rhaenyra was also young (i.e., 14) and a virgin according to every source available. All things Daemon liked, so if for nothing else he would definitely want to have her for the sake of his 🐔 even if it was just as a lover.

4- Given his past with Viserys, I don't put it past Daemon to have seduced Rhaenyra in canon as a sort of... vengeance. Like it's not top 3 motive, but it's there. Like pleasant side-effect of the seduction, and that would still hold true here.

Maybe moving on to Rhaenyra's marriage. Well, I don't think under the scenario of her not being heir that her choice of husband would be as important as it was in canon. While I don't think Viserys would want her married to Daemon, and he might still want to marry her to Laenor, she would definitely not have married him in that scenario at least in my opinion 

Friendly reminder that every source available plus agrees that Rhaenyra only agreed to marrying Laenor UNDER THREAT OF DISINHERITANCE!!!!! Louder for the people who confuse their AUs with canon: Rhaenyra only agreed to marry Laenor because Viserys threatened to disinherit her!!!!!!

Since in this AU of her not being heir she didn't have an Iron Throne that Viserys could take away I see nothing stopping her from telling her father to go and f_ himself and just running away and marrying whomever she wanted. In this AU, she would very likely just refuse and either elope with Daemon or someone else she wanted and wanted her (maybe Harwin).

As for a Dance taking place I seriously doubt it, at least while Viserys’s sons lived. By pushing for Rhaenyra, Daemon would actually be saying that a being the eldest and not being the eldest male was the rule for inheritance. In that case then, his cousin Rhaenys should be the one ruling. 

I just don’t believe that the lords would fight for her if she was not the designated heir. She was not the eldest male child of the king, she had three brothers, and the king had not designated her as his heir. Even if let’s say they really hated Aegon II and Aemond and didn’t want them, they still had Daeron who we are told was quite popular amongst nobles and smallfolk. 

I also have some doubts that Daemon would arrange the murders of three or five people (if we add in Aegon’s sons Jaehaerys and Maelor) like that. Now, if by any chances let’s say Aegon, Aemond, and Daeron all died and only Aegon’s children were left... now then he might see an opportunity there to maybe take over and get rid of his great-nephews (a bit à la Richard III and the Princes in the Tower), maybe... but more than that I doubt it.

Sorry again for this huge delay and I hope you have a great end to the year and Happy Hollidays 🥰