I have considered that this may be stated: "Christī Regēns", emphasising with a capital R and being pronounced actively ruling. Is this sufficient to state?
I wonder that is is not more like, "Christi Cesar Regens" though I have not all of the correct letter inflexions.
It must be careful, if correct, to pronounce Christ as Cesar and not pronounce Cesar as Christ.
Addendum: I concede pronouncing Christ as Cesar is not the answer to what I wish to translate. Is it indeed that "Christī Regēns" is sufficient?