https://www.gamespot.com/articles/destiny-2-nightfall-strike-guide-heres-what-you-ne/1100-6453609/

Following Destiny 2's latest weekly reset, new activities are now available in the game, one of which is the next Nightfall Strike. This one is called The Pyramidion, and it challenges players to get revenge against the Vex Mind that fouled up Asher's arm.

As always, there is a time limit. The specific modifiers are being kept under wraps for now, with Bungie apparently intent on players discovering them when they play.