For a start, the stable expression is "bend into three deaths", and you can curl up, for example.
Now let's move on to the etymology. There is no consensus on the origin of this phraseological unit. Even the meaning ranges from "bend strongly" to "completely break." "Perdition" in this expression has nothing to do with death, it goes back to "bending" by its root. Therefore, "three perdition" is "bend three times." There is an opinion that the meaning is associated with places of torture during the time of Muscovite Rus, where they could bend into three deaths upright.
In this case, death does not mean death in the literal sense, but comes from the word bend, bend. That is, translating from Russian into Russian: to bend three times ... And in Russia there was such a torture when a person was bent just three times. Hence the meaning that has come down to our days follows: doom is death