Uncle Drew and his team travelled several more miles after Saden was done absorbing the shadow core. They are now much closer to the Worm Desert.
Now that Saden had formed her shadow spirit, it was just a matter of getting more cores so she could strengthen it and make it one of her strongest abilities.
With a shadow spirit, she can augment her bow and arrows, strengthening them beyond their current limits. Aside from that, she can use her shadow to move.
She can send her shadow thousands of miles away, and whenever she wants, she can swap places with it or teleport directly to its side.
Unlike the tower, where teleporting inside during danger is impossible, she can easily do that with her shadow. This would allow her to escape grave situations more quickly and safely.
