What made Lauryn unhappy when she transformed into Crimson was the fact that she would lose consciousness at that time. Be that Lauryn herself didn't know what Crimson was doing when dealing with the skull artefact.
Once the artefact was taken care of by Crimson and also the Devils no longer came out to destroy Maple Town. Sebastian also realised that Lauryn had succeeded in doing her job.
No longer thinking about the people pressing him upstairs, Sebastian immediately ran to the ground floor of this place, because he never saw Lauryn coming back.
Sebastian was really worried when he realised this, he hoped that Lauryn would be fine this time. It took a few moments for Sebastian to get down there.
And when Sebastian arrived his reaction was more or less the same as Lauryn when he go
