I loved the dynamic between Raiden and Bladewolf, they start out as enemies because they were forced to fight and then Raiden saves Bladewolf and they become such great friends. There were so many meaningful moments during the story where Bladewolf is inquiring about Raiden's thoughts and feelings, and trying his best to comfort his master, and Raiden returns the sentiment. I also liked how Bladewolf is a very deadpan robot that puts Raiden in his place when he gets into any antics, their friction was very funny to watch. Not to mention the many meaningful philosophical discussions they got into which I though were very fascinating.
This isn't even touching on the fact that he's a robot dog that look totally awesome, and is almost like a ninja dog since he conducts recon for Raiden from the shadows. Not only is he Raiden's friend on a personal level but he actually helps him during his mission. What's not to love about Bladewolf, he's such an awesome character.