the endgame emperors of rome got to do literally anything they wanted for a few months (maybe years) before getting murdered. you could kill anyone at any time, declare yourself a god, marry your sister, whatever, but you were absolutely going to end by the knife. that was just the deal. just riding a moribund empire into the ground dr. strangelove-style.
i mean look at this shit: “ The final collapse of the Empire in the West was marked by increasingly ineffectual puppet Emperors dominated by their Germanic masters of the soldiers. The most pointed example of this is the Suebian general Ricimer, who became a “Shadow Emperor” by deposing Avitus, installing and subsequently deposing (and murdering) Majorian, installing (and possibly subsequently murdering) Libius Severus, ruling the Empire himself during an eighteen-month interregnum, deposing and killing Anthemius, and installing Olybrius.”