[quote=AliceZaru]
Why would two goddess be defeated by the human race? XD
[/quote]

Seras cant be killed. She can experience the pain of death but wake up when the wounds are healed
however if the wounds cant heal (stab a stake though her heart and keep it there) then she wont wake up
Further her powers have been sealed so if she gets trapped in a location without a raw element. Say a metal box. She cant do anything unless she can hope to pierce the lock with her bow. But that could proof tricky with the right trap as its possible to take away her bow if it was outside the poxket dimension

chii is a demi. Half god half human (in her case) so she can be killed and age. She just experiences more natural born powers
though when she reaxhes the age of 21 she will stop aging but this is due to bounding with thw kari so ita not natural born power