First cousin's great-grandchild.
My first great-great-cousin-nibling is a good person.
Child of their maternal first cousin with the paternal first cousin or double-first cousin’s child.
My double-first cousin-nibling is a good person.
1. The grandchild of one's parent's stepsibling.
2. The stepgrandchild of one's parent's sibling.
3. The grandchild of one's stepparent's sibling.
My first step-cousin-nibling is a good person.