How did mercenaries and Attila contribute to the decline and fall of the roman empire?

Oh, dude, mercenaries and Attila the Hun were like those unwanted guests at a party who just wouldn't leave. The mercenaries were hired muscle who caused chaos and instability, while Attila was the ultimate party crasher, sweeping in with his Hunnic horde and wreaking havoc. Together, they were like the ultimate tag team that helped speed up the decline and fall of the Roman Empire.