As for stealing the giant's Great Dao, Han Fei tried it once, but he was immediately counterattacked and had to rely on the Great Dao of Life Replacement to survive.
Han Fei realized that although the giant was created based on his own strength, what bestowed the other party with the Great Dao was not the giant itself, but a god.
However, Han Fei also discovered that the first test didn't necessarily mean there was no way out. The giants frequently formed seals, which was strange in itself. If a person specialized in the Thunder Law, after repeatedly watching the other party making seals, he would be able to learn it or at least imitate it.
Therefore, the real meaning of this first trial was to give the participant a seal technique. It was meant to teach the trial-taker a seal technique, but some people couldn't withstand it at all.