Dilan might be filled with raging emotions, and he might be ready to kill millions of humans or beings of foreign races if necessary, but there were still certain things he didn't want to happen.
This included the death of small and innocent children. They had yet to grow up, mature and face the harsh realities of the world. Small children were the most innocent and purest.
Their purity of minds and innocence was very important factor in Dilan's mind, but the most important for him was that small children were not able to defend themselves against others.
It was the duty of every grown-up person to protect them so that they could survive and thrive. Dilan didn't want to kill small children if it was possible to avoid it.
This was something even his tarnished and power-hungry mind told him, despite being overflowing with all kinds of emotions.