Take it when you own a broad Drukhari collection and want to field all of it, or when you like starting a game with resources rather than earning them. It is also the detachment that most closely matches what the faction's lore actually describes, which counts for something.
Be clear-eyed about the sourcing. This is one of two pages in our Drukhari set where the Faction Pack does not name the detachment at all, so everything except the DP cost, force disposition and enhancement points comes from community mirrors. Confirm the wording in the app before a tournament.
And be clear-eyed about the design. The rule is entirely front-loaded: after the start of the battle it does nothing at all for the rest of the game. Six tokens is a strong opening and no ongoing engine, so a long grinding game slowly erases your advantage. It also charges a real list-building tax for the full six.
Sample gameplan: build for all three pairings, so you start on 6 Pain tokens. Give Dark Vitality to whichever unit has a Pain ability you want running every phase, since it removes the token cost permanently. Spend your opening pile Empowering the units doing the turn-one and turn-two work, and use Labyrinthine Cunning to convert leftover tokens into command points once income catches up. Hold Fighting Shadows and Insensible to Pain for your opponent's turn, and remember which one covers which half of your army.