Blue Ember's target was the seal on her connection to the River of Time, and she was prepared for this attack. First, she used the best Seal Removing Spell she knew. Then, she fused that spell with another boosting technique. The reason she talked so much with her target was that the boosting technique can become more powerful by accumulating strength.
Blue Ember's plan was decent. The spells she used were the best, meaning she used the best cards available to her. Unfortunately, she was predictable. The moment she attacked, Wang Wei reacted by using the skill that he had been accumulating power for.
The technique he used was an old but reliable one: Yin-Yang Reversal. Of course, he boosted it to meet the requirement, but it eventually met Wang Wei's requirements. When Blue Ember's technique reached the seal, another Yin-Yang Symbol materialized and reversed the effects.