This event (Revelation 16:13-14) occurs before the 1,000 year reign when the beast and false prophet are still active. Revelation 19:20 the beast and false prophet are cast into the Lake of Fire before the millennial reign of Christ, Revelation 20:1 satan is locked in the bottomless pit. Nothing is said to escape the Lake of Fire, it is portrayed as finality.

When the 1,000 years are over satan is let out and then achieves a rebellion against Christ - amazing Jesus will reign 1,000 years and still people will reject Him - which is thwarted by fire from heaven and satan then goes into the Lake of Fire.