We all know kakashi in part 1, he would pass out after using his three tome sharingan this would exhaust his body if he used it for too long. But what amazes me is that 3-4 years later in the fourth great Shinobi war he used the kamui I would say at least 20 times or more, used lightning blade and lightning clone jutsu multiple times, and using other Chakra consuming jutsu all in a single day. It was like he transformed into a god, he couldn't have been training his ass off everyday to get this strong, it's impossible. I remember right before the war kakashi didnt have this massive skill increase. He claims his weakness is a "normal Chakra reserve", but it's like he's on par with a jinchuriki or something. I don't think this is explained in the series. Maybe he's popping food pills or something idk
