
If cersei was the wife of viserys instead of alicent, how different things would be? ( rest stays the same)
Based only on show:)

Based only on show:)
People just really consider him evil, but in the show, I haven't seen anything that makes him evil. Honestly, he hasn't done anything far beyond that of Daemon .
What's your opinions?
And he's clearly regretful of his actions. Ig he's past his monstrous behaviour?
Intentional Gap? Missing heir!
In Fire & Blood, Archmaester Gyldayn leaves a massive, unanswered mystery hanging over the Riverlands: What happened to Alys Rivers and Aemond Targaryen’s child?
During the Regency of Aegon III (around 131–136 AC), Alys rules Harrenhal as the "Witch Queen." She explicitly claims her infant boy is Aemond's son and the rightful heir to the Iron Throne. Men who look into her fires die, and witnesses report seeing a hatching dragon at the castle. Then, as the regency ends, the child vanishes from official Citadel records.
Maesters dismiss him as a bastard who died young or was forgotten. But you see, George R.R. Martin isn't someone who introduce a witch holding a dragon egg with Aemond Targaryen's child without a longterm payoff.
How Identity Swap and timeline works:
To connect a child born around 131 AC to Brynden Rivers aka bloodraven born in 175 AC, we have to look at the lore of Harrenhal, blood magic, and court infiltration
I will list out possibilities
Option A: Alys Rivers is "Minisa Blackwood" herself (Glamour / Identity Theft)
Alys Rivers is described in Fire & Blood as looking decades younger than her age, with many believing she was an ancient figure using potions, blood, and weirwood magic to preserve her youth. Using a glamour much like Melisandre does in the Asoiaf series Alys could easily take on the identity of a young noblewoman from House Blackwood (a family deeply bound to the Old Gods and Riverlands magic). By charming Aegon IV, she places her son directly inside the Targaryen royal family, passing him off as one of the King's "Great Bastards" to protect him from Crown executioners.
Option B: The Baby Swap / Weirwood Stasis
If Melissa Blackwood was a real person, Alys Rivers sharing the same Old Gods magical alignment as House Blackwood could have worked directly with her or infiltrated her household. Alys could have used ancient blood magic or the weirwood network beneath Harrenhal to hold her son in a magically induced stasis or extended infancy until the mid-160s/170s AC. Once Minisa Blackwood gave birth (or lost a child), Alys swapped her son in, ensuring Aemond’s bloodline was given royal legitimacy under Aegon IV’s banner.
Option C: Elimination & Replacement
Alys, wanting her son to have the full backing of a major Riverlands house and royal protection, quietly eliminated the real Minisa Blackwood, took her place at Raventree Hall, and presented Aemond’s magically preserved child to King Aegon IV as his own.
Foreshadowing and evidence point by point
The One-Eye
Aemond Targaryen famously lost his eye in a knife fight with Lucerys Velaryon and replaced it with a sapphire.
Bloodraven lost his eye at the Battle of Redgrass Field fighting Bittersteel, refused to cover the socket, and became famous across Westeros as a legendary one-eyed figure ("How many eyes does Lord Bloodraven have? A thousand... and one.").
The Reclaiming of Dark Sister:
Daemon Targaryen killed Aemond over the Gods Eye by leaping from Caraxes and driving the Valyrian steel sword Dark Sister straight through Aemond's eye socket.
Bloodraven later becomes the official wielder of Dark Sister. Poetically, Aemond's true son reclaims the exact blade that ended his father's life.
The Exact Magic Profile:
Alys Rivers was a Riverlands weirwood-witch, vision-reader, potion-brewer, and sorceress operating out of Harrenhal.
Aemond Targaryen brought the royal dragonblood and intense, ruthless drive.
Bloodraven is the ultimate synthesis of both worlds, a dark sorcerer, skinchanger, greenseer, master of shadow-craft, and user of glamours who eventually physically merges with the weirwood roots the exact magic Alys practiced.
The Citadel/Maester Cover-Up:
Fire & Blood is an in universe history written by Archmaester Gyldayn. The Citadel consistently downplays, ignores, or misinterprets high sorcery, dragon hatching, and wood-witch motives. The Maesters reporting that Alys's child "disappeared" is classic GRRM unreliable narration hiding a secret royal lineage in plain sight don't you think? And perhaps alys rivers wanted to create three eyed raven after all?
Conclusion
Alys Rivers did not let Aemond's bloodline die out in the ruins of Harrenhal. By using Riverlands sorcery, age-manipulation, and a calculated tie to House Blackwood, she smuggled her son straight into the Red Keep. Aegon IV raised him thinking he was his own bastard, but in reality, Brynden "Bloodraven" Rivers was Aemond and Alys’s son all along—the ultimate weapon born of Targaryen fire and Riverlands blood magic, whose true path led from the Iron Throne straight into the weirwood roots as the Three-Eyed Crow.