How have you done on previous dungeon events pulling talisman. I went over 450 runs on the eternal without a talisman. Then 500 more until the second dropped, third dropped 50 runs later. Next 350 runs pulled the last 3.

You are not only one with bad luck. It seems some get a bunch others get stiffed. I always thought it was RNG on who gets them, not just how often they drop.