Crit or lethality rengar

So after the rengar half revert, crit rengar is a thing now. I had a crit rengar in my last game as shyvana and it was a horror movie for all the squishies. Not a videogame, a horror movie. And there I was in riot gear essentially no pun intended. Jinx eventually found a weapon and killed the horror movie killer multiple times and that's how they threw. I also kicked the shit out of him as well and killed him a few times. Anyways.i played.rengar a while ago for fun and built lethality and did good but not great. It wasn't a horror movie for the enemy and I wasn't a horror movie killer. I was just a murderer. I didn't feed or oneshot the world but I didn't die at all. I went 6/0 but my adc made me useless because I just wasn't needed. Anyways, should i go crit or lethality for future reference.