After they reach a mountainous cliffside, Shayliss stops the group to lecture them about the danger they’re about to be in.
She explains that the Shadow Lord isn’t like any monster they’ve fought before. It’s a God of death, literally immortal. It can harvest the souls of the ones that die in its domain.
The group is unwilling to turn around. They must save Justice.
Eventually they reach a massive opening in the earth, with a glowing stone floating above it. A powerful magic emanates from the stone, creating a barrier down into the ground that they cannot cross. Physical and magical attacks are both deflected without apparent effect.