I set things ablaze or bring lovers to bed, I pit foes in rings and pair socks in red. What am I?

Face marred by pocks With the eye of a snake Prisoner to chance Cold decider of fate

I stop all the work, I end every frame, I flash in a storm, I change up the game. What am I?

I have keys but no locks, I have space but no room, You can enter, but not walk through.

you use it as a door, but it has no handle. it is theoretically possible to create, but nobody knows how to create it.