We're passing the time
By breaking apart
We're damned at the end
And we're damned at the start
Blame it on the roses
Blame it on the red
We're running out of time
And I'm running out of breath
-Hey Now, Augustana
The air was fetid and humid. The forest was filled with screams and the gasps of the wounded and dying.
Minato felt he was choking on the air he hastily sucked in during the lull in fighting. The blood on his hands made it hard to grip the kunai. He hurriedly swiped them on his already stained-beyond-repair pants. He felt he could still feel the sticky, red fluid on his hands. This was his first combat situation ever; he had graduated from the ninja academy only two weeks prior.
Jiraiya was new to the art of teaching and had accidently stumbled across a full-fledged battle between Sand and Iwa nin. Jiraiya forgot he had three green genin following him like lost puppies, and so naturally the enemy had heard them approaching. Both of the groups thought they were back up for the other.
They would have been slaughtered immediately had Jiraiya not grabbed the other two and thrown them bodily out of the way. Minato dodged on his own but in the opposite way. Jiraiya ran holding what he thought were his two surviving students, trying to get them to safety before he went back for what he felt almost certainly was the body of his third student. There were skilled jonin in that clearing; he'd felt their killing intent clearly, but he was a Sannin and by God he'd get his student back. Even as a corpse, he owed the kid that had been entrusted to him that much.
Minato was panicking. He couldn't see Sensei anywhere. The other shinobi occasionally threw a kunai or shuriken at him, but he obviously wasn't a big fry. Then out of seemingly nowhere, a massive bear of a man with an eye-patch and an Iwa hitai-ate. For a second, Minato felt the kunai pierce him. He felt it slip between his ribs, felt his life blood slip away.
And then, he was behind the shinobi, the Iwa nin's head landed on the dirt beside him staining the brown a deep, filthy red. Minato curbed his sudden and violent desire to puke.
His first kill.
More ninja noticed him after that. They no longer saw him as a green genin shaking in his boots, an at-the wrong-place-at-the-wrong time kid, but as a child killer who beheaded an Iwa jonin before he could even react. Minato had a job and a half avoiding shinobi, kunoichi, and kunai after that.
By the time Jiraiya had gotten his other to students to safety and returned, the battle was over. A young boy stood in the middle of the carnage, crying his eyes out and puking. Minato looked up at him cerulean eyes wide and lifted a kunai before he saw who it was. He collapsed crying hysterically into his sensei's flak jacket. He's one hell of a kid. I guess this is what you would call a genius. Even Orochimaru couldn't have survived this as his first battle.
In a dark forest stained red by the blood he had helped to spill, a Konoha genin was tested by fire and blood, and yet survived.