Fire

Sakura reflects that fire is angry. It's a burning flame that licks at you, singing your defenses. It turns your skin black and marrs it. It gives you blisters and angry oozing wounds. She thinks that fire is the most dangerous element.

Naruto thinks that fire is useful. Without it, he would not be able to make ramen. If they didn't have fire, ramen would be just hard noodles without any flavoring. He also thinks that if they didn't have fire that they'd all be dead. Fire kept them warm on the outside, even if they were feeling cold on the inside.

Sasuke thinks that fire is the best element. Fire jutsus are his best, he enjoys shouting 'Katon' just to see the look on Naruto's face. He likes how the fire he can create can take different forms. It can be phoenix flower jutsu, fireball jutsu, just a plain breath of fire and a whole bunch of others. He also thinks that those techniques are some of his most damaging. Briefly, he wonders if it's ironic that Naruto calls him Ice Queen when his element is fire. He decides not to dwell.

Kakashi muses that fire is hatred. That fire is the burning feeling of desire, hatred, anger, frustration, annoyance and sometimes passion. Kakashi thinks that fire has pros and cons and that Naruto was right about everyone being dead without fire. He's sure that if they didn't have it, people would be lost. He also sure that Sasuke is the burning definition of fire.

Sai thinks of all the little sayings that involve fire. 'Play with fire, you're going to get burned' 'Like a moth to a flame' 'Hotter than hell' He thinks that fire might be bad, and that it's very unstable. He notes that Sasuke's favorite jutsu are his 'Katon' jutsus and that it would fit for fire to be bad and unstable. He wonders what it's like to be able to manipulate fire like he does but decides he's better off not knowing.

Yamato thinks that fire is how people are born. Everyone is born innocent and pure, but with a bit of fire. He thinks that without fire, people would not be the same. There wouldn't be love the way it is, and everything, emotions would be even duller than they actually are. He thinks that if there was nothing but dullness, the world would kill itself.

Apparently, fire was needed to survive.