Revelation 19:20
Then the beast was captured, and with him the false prophet who worked signs in his presence, by which he deceived those who received the mark of the beast and those who worshiped his image. These two were cast alive into the lake of fire burning with brimstone.
this means the beast and the false prophet are cast alive into the lake of fire with brimstone, which is sulfer. stinky stuff...
Revelation 20:10
The devil, who deceived them, was cast into the lake of fire and brimstone where the beast and the false prophet are. And they will be tormented day and night forever and ever. This is when the devil joins his two buddies in that lake and they will be tormented day and night forever and ever.
Revelation 20:14
Then Death and Hades were cast into the lake of fire. This is the second death. the first death is physical and temporary. the second is the lake of fire for eternity
Revelation 20:15
And anyone not found written in the Book of Life was cast into the lake of fire. if you are not written in the Book of life you get cast into the lake of fire.
Revelation 21:8
But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death.”