He is a bit too nice to be Beckett, but he goes in that direction. I somehow can't see Halsin breaking into a nightclub to steal a book that belongs to infamous Sascha Vykos (one of my favorite npcs in the WoD btw) or trying to trick Dracula and survive to tell about it. But yeah, Halsin is certainly the guy that knows a lot and can turn into an animal.
I don't know, Halsin broke into a goblin camp with drums on every corner to track down a Nightsong... and it looks like we are heading either to the Shadowlands, Barovia or the Outer City Cemetery to face against a vampire lord with Bela Lugosi vibes. He even supervises the written History of the Grove (like Beckett) and seems to have a tragic love story in his past (like Beckett), to the point that one of his apprentices is writing fanfictions about it.
Ok, I see the similarities. Cazador sounds a bit like a cliche Tzimisce. I hope, when we meet him, he is a bit more fleshed out than it seems atm (if wee meet him, I might just strangle Astarion before that).
But I never catched on the tragic lovestory of Halsin. Is that in a book lying around in the grove? I thought, I've read them all. I always thought, he and Kagha might have history. When she dies, he seems to take her death very personal. On teh otehr hand, he never even looses a word about Nettie, his apprentice, being dead, if you kill her.
Did you read Becketts Jyhad diary? It's so much fun. The chapter where he and Vykos had to work together was hilarious.