Overall, Lew seems like the kind of guy who is passionate about fictional and non-fictional animals, adoring them and talking about them in a similar matter that a zoologist does. He portrays a similar, but more subdued interest in Japanese media, and is probably the guy you go to if you want a new VN or something. One thing to note is that Lew's also surprisingly not militant about his interests, either, and is the type to welcome anyone to his broad range of hobbies.
The only thing that he doesn't openly broadcast is his more "weird" interests, but even then he at least doesn't actually creep on about them like he does IRL.
Uhh if anyone wants to know Lew for more than 4 years, I can say he was a very different individual back in the day.
Teen!Lew was a toxic shut-in who ranted to his closest confidants about how shitty the gacha was, and passively criticized others of their tastes if any monster girls were brought up.
Adult!Lew was probably a slow development into maturity rather than a full 180. Maybe it was because he finally had his own house and wasn't a shut-in leech for his parents, or maybe because he was done being bullied in school. While Lew never shares much about his personal life, he does seem to talk about animal encounters a whole lot, so the only thing that's obvious about him was he works with animals to some degree. In any case, he's now wayy less toxic about things, but he still groans about the gacha to the close online friends who knew him before.