Arcane Enigma is the second ability for Rose in Plants vs. Zombies: Garden Warfare 2. The ability is similar to the Scientist's Energy Warp, turning it immune to most damage and allowing it to travel faster. It can also be used to deal area damage pulses, dealing 20 damage, at the cost of 25% of the energy bar. Arcane Enigma has approximately a 1 second cast time.
Only Rose could make transforming into a being of pure, invulnerable, damage-dealing energy seem so easy.
Arcane Enigma is a good way to both protect yourself from incoming damage and destroy your offenders at the same time. However, its duration is rather short, and its damage isn't that amazing.