[Rupert]

The geas is a separate issue, but normal Unkillable III has this: "Once you are at full HP, your fully intact body will coalesce in a location of the GM's choosing." Therefore, there's no need for anything special to be added to the Unkillable to deal with the 'save point' - the GM just decides where it is each time - there's nothing that says the GM must choose once once and it's then fixed, or that they can't entertain player suggestions. The player getting to set the ress point would be worth points, though.