diegosays :
Why, when he had both pieces, did LG not time travel back to just before the rebellion and stop LR? Instead he said that he needed LR to also enter with his half which will basically be the plot of episode 16. This would suggest that even with both pieces, there are limits to where you can time travel.
The show is kind of contradictory on the uses of the flute.
From LR point of view, and just from logical thinking the Flute allows you to travel anywhere in time, past and future.
But according to yoyo boy, your only able to travel back to save yourself. Whether saving yourself means saving your life, or saving from failure or other ways of saving yourself.
Since the flute is cut in half and was stained with the blood of LG and LR. Each side of the flute chose an owner so to speak, so LR can't use LG's flute and vice versa. But LG will only be able to time travel to the point of the coup if both LG and LR's flute is in the time space zone at the same time.
That is why he is telling Shinjae to escort LR, and once LR is in the time space zone. But plot twist, it will be TE who will be escorting LR, and both LR and TE will probably go to the night of the coup also.
We also see in Ep 15 that when LG was holding the flute, an obelisk with red colration appears. LR mentions that this is the obelisk he has been searching for, meaning this is LR true plan, to go back to another timeline, way before the coup, most likely when the grandfather of LG was choosing his heir perhaps.
LG enters here briefly,, and wonders where this obelisk would lead him. We noticed right away the time space zone here is very different from the shared time zone of LR and LG. It's importance hasn't been shown yet.