Queen Chrysalis

Queen of the Changelings, Chrysalis used Twilight's brother in order to gain enough power to rule over all of Equestria. In the end, however, it was the love between Shining Armor and Princess Cadence that defeated her.

She is voiced by Kathleen Barr

HailFire Empire Storyline
She joined forces with Phantom and helped him exact his revenge upon those responsible for his exile.

Totally Mobian Spies
She helps out her old friend the Iron Queen. Her shaping shifting helped frame Eddy for a crime he did not comment. However she left before the fina fight seeing that Iron Queen was gonna fail.

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Fire Rebellion Storyline
She opposes the Order of the Just and Blue Flare. She is a danger to both due to the fact that she can use her powers to infiltrate either as a mole. However, Queen Chrysalis is not as much of a threat to them as The Meta is, but coincidentally is an ally to Sigma, the A.I. responsible for The Meta.

Both Chrysalis and Sigma had manipulated General Dayton to the point of the latter threatening to destroy Equestria with Tungsten Missiles from the LOKI Space Weapon.