Langit needs one year to travel around the entire globe in order to trace everything. The information from the Himalayan men did not satisfy him, so he finally tried to go around the entire barrier and observe everything in silence.
What the Himalayan men said at that time was true. Wrenas who come to Earth by accident can't come back to Yamani, no matter how hard they try. Langit has seen it many times. There are many wrena who are stuck on Earth and can't come back.
Even if they wanted to fight the humans and finish off the living things, the humans would definitely have an easier time killing them since they were outnumbered.
He could also see clearly from a height that the islands in Nusantara were indeed quite separated from other landmasses in a wider part of the continent. They really are like a bridge between Earth and Yamani, and the majority of wrena also fall there.