Yay all are happy

We'll be sure to research how Cozy Glow got out of her stone encasement.

I’m one of the people who kinda didn’t like the fact they petrified her XD

Technically speaking: Cozy Glow herself wasn't put into stone. What the others were fighting against was a Familiar, an animal ghide that could shapeshift from their normal form to that of their Masters' form in order to complete tasks for them. Cozy Glow was fortunate enough to have two Familiars named Mabel and Grip, whose natural appearance was that of a pair of Ravens. Grip was cautious and methodical, whereas his partner Mabel was more of an emotionally-driven risk-taker and whom was the "Cozy Glow" we actually saw on the big screen.

The real Cozy Glow was actually determined and strong-willed, those who had joined her side over the course of the decade had saw Cozy Huginn-Muninn Glow as a sort of War God due to how quickly she can turn the tide of battle in ones own favor. She lived withjn the shadows of Equestrian society, working to try undoing the mistakes caused directly and indirectly by Princess Celestia that ranged from saving the Diamond Dogs from a vicious Maulwurf after the events of A Dog and Pony Show, to freeing "Gusty the Great" who was uknowingly used to power the Ascendancy Spell that was used to make Twilight Sparkle into an Alicorn. Her latest exploit in Equestria was actually during the Three-Days Invasion of Equestria by The Storm King: where she led her gathered forces headlong into battle and by the third day managed to wipe out over 96% of the total invasion force and armada, prompting The Storm King to start recalling his forces back to Canterlot to protect the ritual site when Tempest returned with Twilight. The shot of the skyline in the movie after Open Up Your Eyes? That was pretty much all that was left of The invading forces as they retreated to fortify Canterlot, the few that hadn't gotten away fast enough were holed up in the now-burning Ponyville being butchered by Cozy Glow and her followers in preparation for a full-scale frontal assault.

After The Storm Kings' Defeat by Tempest in Canterlot, the Declaration of Annihilation was unleashed back towards the Satyrs island home of New Tambelon, meant to begin the Satyrs Extermination Campaign by destroying all complex life on the Mainland. Naturally due to Celestias' ignorance she never knew of the existence of such a message and based on previous experience Equestria was not only ill-defended against such an invasion by what The Storm King had that amounted as a mere Reconnaissance Fleet in-comparison, but that she was completely reliant upon Twilight Sparkle to serve as her personal lap dog: a pony who had no knowledge or business at all being within the horrors of complete and total war. Leaving Mabel behind in Equestria, Cozy Glow and her followers managed to travel south and then head west after recruiting both the Porcupines and the Abyssinians' savage cousins the Saberon before lanching a full-scale invasion of the Satyrs fortress island of New Tambelon in a siege that would last for two years.

On the last day of the Siege, Cozy Glow and her Alicorn Followers managed to breach the inner sanctum of the Satyr capital, built into the Calderra of a dormant volcano, carrying with them a nuclear warhead they planned to detonate underground to trigger the volcanoes eruption: one strong enough to wipe both The Satyrs and their entire island off the face of the map. Due to her Alicorn Nature, Fozy Huginn-Muninn Glow was formidable of an opponent and highly unorthodox combatant who would often fight on the frontlines directly, tanking damage and lethal blows that her Healing Factor could shrug off and regenerate from, coupled with how despite Celestia's best attempts at removing her Alicorn Nature ten years ago, only removed her Unicorn Magic while it gave her the chance to instead amplify both her Pegasus Flight and Earth Pony Strength to the highest degree, one that Celestia had constantly overlooked in-favor of using just her Magic alone. During the course of the final battle, the Satyr Emperor personally fought against Cozy Glow and managed to near-fatally stab Cozy when the magic from the Elements of Harmony traveled their way into Cozy Glow through her ethreal connection with Mabel that removed her Healing Factor entirely at the critical moment. While the mission was a success as the island fortress of New Tambelon erupted in the hellfire of volcanism and radiation, Cozys' condition was now critical and prompted for them to return to Equestria to try and save their leader at all costs: even if it meant becoming the enemies of a nation they had saved and whose princess of the Sun saw Cozy Glow as a monster instead of her own outcast Daughter.

Jesus fucking christ