One question that would have derailed this whole reveal.

Vernal appears to be summoning storm clouds in front of Cinder, Dr Watts, Emerald and Mercury, when it's actually Raven
Cinder: Why don't your eyes glow?
Awkward silence between Raven and Vernal as Raven tries to come up with an answer and Vernal's glancing at Raven for an answer all without trying to ruin the surprise

Good thing the display of power was distracting enough to look away from her eyes.