The Lightning Armament spell was Voronoi's trump spell. He used it to great effect against Ghost Flash in the previous battle. In the view of many apprentices, if it were not because of Ghost Flash's mysterious abilities which were overwhelmingly powerful and sneaky, coupled with the injuries Voronoi sustained as the battle had gone on, then he might have emerged from that battle as the victor.
This time, knowing the caliber of the opponent standing across him, Voronoi did not hesitate to use his strongest cards from the get-go, taking lessons from his previous defeat.
The Lightning Armament spell boosted his physical prowess and increased damage from his lightning elemental energy. Hence he was confident ability to battle August.
