The upcoming league of Path of Exile, which has the nickname of "Betrayal", brings some new features: new masters, Atlas Objectives, and the Immortal Syndicate are just a part of it. In POE Currency a subordinate clause, the developers had also announced something they did not explain - scarabs (Scarabs).
Because in the blog entry to the new masters the sentence "Note that you can use Sextants and trade for Prophecies or Scarabs to run Delve more frequently". Translation: "Note that you can use sextants and get prophecies or scarabs via trade to make Delve missions more often". The joke of it is, however, that up to this sentence was never spoken of a scarab.
While the rewards for 12 or even 24 regular game challenges are not a major hurdle, the rewards for 36+ tackled challenges are often just the most hardworking of the POE Chaos Orb hard-working ones. So if you want to secure the Cape of the Betrayal League, you need time, a strong build and a plan. Some challenges that require certain random encounters are sold in chat, for example. If a player has such a Random Encounter, you can ask him if you can join his group.