Sol was placed firmly on the back of Secim. Placed would be the correct term to use here, as due to her inability to move, Fren had moved her on top of the young Jolin. She was barely mobile and needed a rest, but they were too far away from Fren's home to return without losing far too much time. Of course, there was also the worry of the blizzard from before returning, leaving them stranded for months.
So, they saw the only solution in continuing to descend. Now that they had gotten over the hurdle of slaying a Wyvern, Sol believed they had plenty of time to descend.
And time was all that was needed. Lua's, or Sol's, body was completely battered. It was barely functional, and the only way the body was still alive was due to Lua's strengthened physique.
The Necklace of the Embers had also been cracked, likely due to absorbing some of the blast from the explosion.