Clearly, Danny has a single Iron Fist, from the moment he was granted it. He only ever uses a hand, and the same hand, to manifest the Fist.
However, when .
Davos takes the Fist from him
he ends up with
Clearly, there's no "conservation of Fists" here.
ends up with a single Fist
particularly having only one Fist after the ceremony.
Seemingly, in this case, the number of Iron Fists does stay constant.
What determines how many Fists a person gets?