When Lin Li was in the Endless Void previously, he did not continue to explore the inverted tower, partly because of the time constraints, and partly because he felt that he was not capable enough. This time, Lin Li had already successfully reached level-27, and with the guidance of Geresco's incarnation, there had been shocking changes in his strength. Hence, when the rate of his improvement reached the doldrums, Lin Li felt that it was time for him to further explore the inverted tower.
Thus, when the representatives of the various forces of the Breezy Plains once again went to the Tower of Dusk in a bid to get Lin Li to step out and take charge of the alliance, Lin Li had already stepped through the door of the inverted tower.