I think for zarude she could challenge the MC as soon as she sees him and refuses to stop fighting after the MC win because zarude is said to be incredibly aggressive
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They usually stay in groups so if the MC goes to them he would face many at once. There is Dada Zarude (or can be renamed Mama Zarude) who has a softer side but would still be aggressive to the MC and attack but be by herself. She did raise a human infant so she would definitely love to be breed and have kids. It can also work that the girl that wants to see Zarude be the infant grown up and wants to see her again and reward the MC.