After thinking for a while Kayle headed towards Karin's team, he quickly found them but didn't want to act too quickly and hid not too far from them while monitoring them.
The more Kayle watched Karin's team interact the more he got angry, at first Kayle was very confused, he couldn't understand why this team was very slow. But as he kept a close eye on them, it finally connected in his mind.
Karin had her chakra unlocked but she had no training at all, it was clear that any student that didn't even graduate from the ninja academy could easily defeat her, her sole purpose in this team was to serve as a healing battery, whenever one of her teammates got injured he would go and bite her to heal himself not caring one bit of her.
Kayle watched this for a few hours, at first his only goal was to take her with him, but now he had to put a lot of effort to control himself, her two teammates were going to die. The decision was made and it would have no repercussion at all on him, this was the chunin exam, everyone knew that they were allowed to kill each other if needed.
As the night fell down, Kayle finally saw an opportunity, both her teammates separated from her and let her stay at the campsite they had established as they went to look for food. Kayle slowly followed behind them making sure to not be noticed and once estimated that they were far enough he finally decided to strike.
The two genins from the Village Hidden in the Grass felt lucky, Shigeri was one of them, he was the grandson of one of the village's elders, as he wasn't very confident about passing the chunin exam while relying solely on his strength, he had asked his grandfather to let him borrow the tool with the special healing power.
It took him quite a lot of convincing but he succeeded as he explained that she could be used in the future by everyone to succeed in the exam, this way their village would get more chunins which would help attract more missions to the village.
Unknown to him, the way he had treated the "Healing tool" has sealed his fate, Kayle wasn't a sadistic person, he didn't enjoy making others suffer unless they really got to his nerves. Right now he only considered the two ninjas before his eyes as trash, the world would only fare better without them in it.
Without wasting any more time Kayle silently appeared behind them, like the god of death he loomed behind them for a second before disappearing once again. The two ninjas that were talking while moving in the forest slowly came to a stop, from a casual conversation to the moment where their heads fell off to the ground, at no point any of them did see their death coming.
Kayle that just took two lives felt a little scared... until now he had enjoyed fighting people, and didn't care one bit about ending their life, but for the first time in his life, he had executed someone. the difference in strength was so big that when assassinating them they stood no chance at all.
Kayle: '...So that's what happens when the difference in strength is too big... No wonder Minato could kill a thousand ninjas alone on a battlefield...but I can't help but have a bitter feeling about it... I didn't enjoy it one bit'
Kayle didn't regret doing it as he knew that the two ninjas he had killed had a lot of innocent blood on their hands.
Kayle: 'I need to get stronger... strong enough that I don't have to worry about letting my guard down'