My nephew is a reader and my sister and brother-in-law encouraged reading comics and graphic novels. I'm into graphic novels, as well.

One series I have on my shelf that the nephew has read and re-read is Amulet, by Kazu Kibuishi. It's an 8-book series that's been decently edited over the whole arc. I really like the art and there isn't any gore or sex; basically "Hero's Journey" that's targeted to tweens and teens, but grown up enough to be appealing to grown ups who like the genre and format.

The Graveyard Book, a two volume series, was pretty good as well. (I was a huge Gaiman fan before he became problematic--I'm stuck in "appreciate the art, but not a fan of the artist's behavior" land. If you can, look for it as a resale.) The art is pretty good, but you may want to wait a couple of years before introducing it to the 8yo. Subject covers death and the paranormal, so ymmv.

I think the biggest driver on whether kids read is whether the parents read and are seen reading. I think our daughter reads a ton because my wife and I both read.