Since he was rambling about vampires before, Tish is going to take a certain amount of convincing now.
Especially since he got the tar kicked out of him despite all the anti-vampire stuff he had on him.
Art-wise, I like how his hair resembles the mane in lion form. Also the intermediate step between man and lion is kind of cute.
From Tish's words in the last two comics I get the idea the Leo isn't exactly comfortable with being a Were. He almost never uses that form and Tish is quick to say he is still human. That suggests that either he is ashamed of this, or he grew up in a culture that considers Were's monsters (http://dhscomix.com/acomic/acomic.php?p=pwere)