Mark 5.10-12: And he begged him earnestly not to send them out of the country. (11) Now a great herd of pigs was feeding there on the hillside, (12) and they begged him, saying, “send us to the pigs; let us enter them.” (ESV)
What began with Legion speaking for the group of demons ends with a plurality of demons speaking to Jesus. And as the English Standard Version translates it, they were “begging” Jesus not to send them out of the country. Luke 8.31 records more specifically, “And they begged him not to command them to depart into the abyss.” (ESV)
The word “abyss” in the New Testament is also translated as “pit” or “bottomless pit”. The abyss is the place where certain demons are confined while they wait to be judged by Christ. Revelation 9.11 says that the king of the abyss is a demon named “Abaddon”, whose name means “destroyer”. Revelation 11.7 says that the abyss is the place from which the beast comes forth. And the last reference in the New Testament regarding the abyss, in the 20th chapter of Revelation, says that it is the place where Satan will be bound for 1,000 years.
All of these references to the abyss and Abaddon and the beast and the devil might be considered intimidating in their natural expression. But in every case God is in control of the coming events. Revelation 9.1 refers to the “key of the pit of the abyss”, which means God in His sovereignty holds the decision making authority over opening and closing the abyss. And there is only one key. Abaddon may be king of the abyss, but he is imprisoned in it. Abaddon is not in control, even though he holds the title of king of the abyss.
And since God is telling us in the Book of Revelation what is going to come to pass at some point in the future, He is in complete control of the future. Not these forces of evil in their various forms. And in this case of Jesus and the Gadarene demoniac, Legion and his group are the ones doing the begging.