Destiny 2 players who put in the effort in the Pale Heart can be rewarded with additional Prismatic parts, Bungie said in a May press conference. Guardians, however, will still earn Aspects and Fragments simply by playing The Final Shape campaign as intended.
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“We really wanted to create a satisfying journey, not only through the Pale Heart, but also through Prismatic, since they’re connected in some way,” said Ben Wommack, Destiny 2’s combat zone lead. “You’re rewarded with finding new pieces as you progress through the campaign, and there are other ways to find them by exploring the destination as well.”
Prismatic takes center stage in the new expansion, with the Traveler's Pale Heart setting the stage for the showdown between Light and Dark. The new subclass is a result of that clash, though its buff appears to be different from Beyond Light's Stasis and Lightfall's Strand.
Guardians can "fully unlock Prismatic by playing the campaign and the journey in Pale Heart" during the first week, even before the raid begins, Wommack said. "Nobody goes into that [the raid] without Prismatic options available if they don't want to."