Who owns the bitcoin after someone died? How to state this in the will? Please share your thoughts.
No one owns it, because it will remain on the wallet if the access to the wallet is not transferred to some one before the owner dies. Even if someone lose their access to their wallet, no one will even be able to use that bitcoin. So, it is better to make sure that some one in your family or some one you trust knows your access to your wallet.
Of course, if you are going to just give away your passwords, go there to your relatives, so that in case of an accident your Good is not lost, then all of this needs to be taught to your relatives, at least to the original basics of crypto currency.