Daenerys named a dragon after her late evil brother, but she had a reason.
It is a fact universally acknowledged that George R. R. Martin shows no mercy to his characters, often putting them through the worst kinds of violence, betrayal and despair. Dozens of fan favourites have been murdered and mutilated, all to build a realistic world with as much death and suffering as the one we live in.
Martin's most famous female character, Daenerys Targaryen, had to go through all sorts of trials and tribulations before she finally got the much-coveted Iron Throne.
As descendants of the Targaryen dynasty that once ruled all of the Seven Kingdoms, Daenerys and her brother Viserys always struggled with their status as outcasts, living in poverty and seeking to regain the power their family once held.
When viewers first meet Viserys, he is already cynical to the core, essentially selling his sister in marriage to the barbarian Khal Drogo with an understanding that Drogo will lend him his army to reconquer the Iron Throne.
When Viserys was brutally murdered, many fans agreed he got what he deserved, but Daenerys still named one of her dragons after him, despite all the suffering and humiliation he put her through. Why?
Many fans on Reddit agree that when we first see Viserys in Game of Thrones, he's already a broken man who's effectively been driven insane after selling his mother's crown.
But Daenerys knew him before that, and it was his protection and help every step of the way that allowed her to survive in exile. In the original books, Daenerys often reminisces about her childhood when Viserys was always kind towards and protective of her, always trying to make her life a fairy tale.
It was only from her brother that Daenerys learned about her family and her rights to the Iron Throne: he taught her how to be strong, and she never forgot those lessons. So it was the kind and caring Viserys she remembered that she named her dragon after, recognising that the good he had done outweighed the suffering he had later put her through.