A quick sketch for another idea I had in mind…

Double trouble :

This is a room that attracts maso in pairs. In the middle are two perfectly symmetrical setups, with two large spiked dildos, electrodes for the nipples, clitoris and collar.
Behind each setup, there's a large articulated metal whip.

To get out of here, the two masochists have to fuck the dildos for 6 hours without stopping, being perfectly sycronized and symmetrical.
They can choose their rhythm together, but this will determine the whip on their backs. If they go slow, the whip will be extremely brutal and fast, if they go fast, the whip will remain a challenge but will be more bearable.

The rest of the setup is there to make them fail. Spiked dildos can blast burning water into their holes, grow brutally, send out huge electric shocks or start spinning, reducing their asses and pussies to a mess.
Electrodes on the rest of their bodies also send out huge discharges.

All this is activated at random, sometimes all at once, and on just one of them. If the one being tortured reacts and breaks the symmetry, the other is punished. She suffers 100 times what the other has just taken. Then the timer resets to zero for a new trial.

The purpose of this room is to drive masochists to sadism. This sometimes produces rare entities that are both sadistic and masochistic.

Gradually, one of them will overtake the other and fail on purpose.
If one of them breaks the symmetry without any torture being the cause, voluntarily or not, she has to say exactly what punishment she thinks she deserves, she suffers it once, then the other suffers it 100 times, and the timer starts again at zero.

Those who fail voluntarily have many possibilities: they can name as many times the available tortures, alone or in combination, choose the power, violence, rhythm, duration… But they have to test their own medicine once, before seeing the other suffer the same thing for long minutes, or hours…
During the other's punishment, the sadist must continue the combination of fucking and whipping, and if she stops for more than a few seconds, she takes the punishment too.
If the sadist comes during the other's punishment, the other takes a maximum electric shock from both dildos and electrodes at the moment of the sadist's climax.

If one or both of them drops from exhaustion and stops fucking the dildos, all the tortures and the whip are activated, still at random, but without resting and at short intervals and maximum power.

To get out of here, the sadist has to decide to stop playing and the two synchronize for 6 long hours.

It's a process that can take weeks, and in the end, one of the two masochists is likely to have become an entity, which may well want to continue playing other games with the poor, just-released masochist.