Honestly I just mentioned "dark rituals" because it sounded cool :P
The only real rituals that I can tell you are involved with him are the ritual to become a skin walker, and the ritual to gain a new transformation. After that, maybe just the rituals to prepare his bones and corpse dust. Otherwise, shooting someone with a tiny bone dart ain't gonna do much, you know? . . . OK yeah, I guess the rituals are kind of important now that I think about it, lol.

As for what they entail? Err... I dunno, I didn't put that much thought into the specifics. Probably some creepy chanting and blood, robbing a grave or two, you know, the usual. I was thinking that since he won't be doing many of the rituals that it would be more of an assumed off screen kinda thing.

The new animal ritual would just be him wearing the pelt and focusing on learning its essence though. 

But really, aside from the animal pelt ritual, he won't be doing very many rituals. He won't even be getting many new animals. It's not like he's going to summon demons or curse anyone from a mile away. The rituals are probably the smallest part of his magic, since aside from preparing his bones, he won't have a need to use them very often. 

That answer your question?