How long was Shi-woon trained by Goomoonryong? In The Breaker, how long was Shi-woon under the tutelage of Goomoonryong? I was under the impression that it was only for a few weeks most of which were spent improving his stamina. As far as I can remember, he was only taught some basic techniques. Yet, he keeps pulling new Murim tricks out of the bag on a regular basis.
He spent only few weeks with the Goomoonryong where:


he got stamina training, but actually not that much
he got the medicine that actually increased his stamina and his ki
from that, he got a lot of training on how to circulate his ki around
the soul crushing technique was shown to him once
the 4 different foot techniques were shown to him once each
and the most important, at the end of the breaker, he gave him a smart phone with many videos to show him new techniques and random advice.


On top of that, he was shown some techniques only once, and he managed to replicate them, although they were supposed to be difficult. So in fight, we can assume he can do the same. Shi woon is a prodigy.

In the breaker new waves, even in a second state (under the black origin thingy), during the school arc, against the SUC, when facing the lone wolf, he managed to replicate the techniques easily, even in a state where he can't even think.

So to summarize, some solid basic trainings, then many videos to improve by himself on top of the fact that he is a prodigy.

Also, with the inner training technique he received in the breaker new wave, he is able to train in his mind, so it might make things easier to try new things.