Practising killer moves was not easy, the Gu Immortal could suffer backlash and injuries with just slight carelessness.
The more powerful the killer moves, the greater the risks. But it was necessary to practise as well, they could not just use killer moves blindly during a battle, right? In fact, the environment during a battle was worse as there would be strong retaliation from the enemy.
There were many cases in history where Gu Immortals failed in activating their killer move and faced the backlash, suffering deep injuries and even dying.
Among them, there were plenty of cases where they died while practising killer moves.
Fang Yuan was practising five restriction profound light qi which was a very powerful killer move, so he was extremely focused and careful.
He had yet to choose between five restriction profound light qi and five regional limit formation.