0C2R
Zeroth-cousin-twice-removed:
1- grandpibling (grandparent's sibling)
2- grandnibling (sibling's grandchild)
1- grandpibling (grandparent's sibling)
2- grandnibling (sibling's grandchild)
My grandpibling is my 0C2R in theory and my grandnibling is also my 0C2R in theory.