If being cast into the Lake of Fire does not result in destruction, then what of Death?

For those that maintain that the soul is not destroyed in the lake of fire, but instead results in eternal suffering, how then do you interpret death being cast into the flames? Revelation 20:14 (NASB) > Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. Is "Death" merely tormented or is it truly destroyed? What would it even mean for death to suffer?