"We shall." Echo replies, using the first effect of the Arc of Time to first send Ren into the grounds, then Shikyo, then himself. He wanted to ensure the boy was trustworthy, anyways. Albeit, Shikyo was there now with Bastion and Keita's powers to interfere, should anything go wrong. As Echo vanishes, his gun disappears, for the break-time of the Arc of Embodiment had met its end, and so the gun was now rendered non-existent. It was time the three faced nullification magic.