"Orphans are indeed pitiful, children who suddenly lose their parents in the war are more vulnerable than those who are abandoned from the beginning, and it is objectively necessary to show them compassion and help. But the child's situation is special: he is human, and he harbors a position and will of revenge against the colonel."
Whether from the subjective will of the individual or from the objective perspective of the whole, the only correct course of action is to wipe out Hruodland d'Arc.
"I bear no personal grudge against the child, nor will I demand his execution simply because he is a human child, or the son of Rinaldo Darkay."
To take out your anger on someone simply because they are a relative of a criminal, to inflict cruel punishment on them—this idea is childish and foolish.
"Adopting this child will inflict unprecedented harm upon you, colonel."
Brynhild's viewpoint always takes the general situation into account, occasionally subtly infused with personal emotion.