Zhao Yuanzhen's strength lay in her ample combat experience and extremely quick on-the-spot reactions.
After all, she was from the Demonic Sect, where survival of the fittest and constant conflicts were rampant, so it was only natural that she was experienced in combat.
As for so-called on-the-spot reactions, it wasn't Lin Ning's best reaction speed, but rather a kind of combat intuition developed later—take, for instance, an unexpected enemy suddenly attacking; Lin Ning might react more quickly, but by the time she decided how to counterattack, Zhao Yuanzhen had already made her move.
When facing danger, the ability to counterattack reflexively without a second thought was Zhao Yuanzhen's greatest advantage.
However, it was also her flaw.