Given you're allowed a maximum of 10 Torments before you need to purify, and how some Ordeals hardly give you that, you will probably see this in around 15 runs or so through the Ordeals themselves. If you feel like speeding this up, the first Optional Ordeal in Chapter 1 gives 10 per run if you extend the full map, meaning you could lessen this as soon as you open it up.