When the deep-blue hue of Fleur's Transcendent Spell faded, the Oceanic Prison and the five demonized Transcendents were nowhere to be seen.
Boris' Spell was disintegrated by the Transcendent Spell but the five weren't. At the last second, before they were engulfed by her spell, the five demonized Transcendents combined all of their Dark Energy or whatever it was they did to withstand it. Nonetheless, the five were still pushed back and took the full brunt of the Spell with their bodies. Their bodies, after being hurled upwards by it, dropped down to the ground which created a small crater where the five of them lay there, state unknown.
When Fleur's Transcendent Spell was unleashed, the ensuing battle or rather one-sided battle against the Dark World Mortals and Noxians paused since everyone got drawn with that mesmerizing spell.