You might think ashfur became a villain because he loved too much, but this is why that's not true.
1. He betreyed his clan. I know that you think he's really a "good cat inside." But he had a dark past. His mother was killed by tigerstar. ( the evil one ) and one of tigerstar's sons was brambleclaw/bramblestar. Ashfur has that right to hate him. But not the right for the love. But back to how he betreyed his clan. So he did because well... He was gonna KILL one of his clanmates. Well such as Hollyleaf, Lionblaze, and Jayfeather. Can you belive that!? It is agenst the warrior code to kill a clanmate!
2. he gets revenge it a really evil and bad way. Well remember that part where he becomes bramblestar's impostor? Well I have not read that book, but I know that he was the imposter https://warriors.fandom.com/wiki/Bramblestar%27s_impostor well i can say I know he's the real villain.
3. I just know that he's evil. Well YOU might think that he's not the real villain in the books, but I mean this is just my opineon. You might think differently. So, well, I mean, yeah. Well I hope that you enjoyed reading this!!!