Who is the better hunter?

Depends on what you're looking for. Warwick's good at following scents and brute force killing his prey. Rengar's got a more tactful approach to things and the whole invisibility deal, but is weapon reliant, unlike Warwick who's got that built in.

In the end I always go back to this:

"You can't even kill an insect."

Can't really argue with that since it's true.

Rengar's a cat. He relies on stealth and ambush. Warwick's a dog, an endurance hunter who runs his prey down. It's two different things.

"There is little mystery about her to me - she is the ultimate predator." - Jax

I mean, if JAX says that, it must be true... Evelynn is the best.

And i dont care if its the old lore.

Well Rengar seems to be the more experienced hunter but from what we've seen with Warwick, he's got more going for him with his amazing sense of smell and bat ears. So I think I'd have to say Warwick.