Ardea's secret weapon was a powerful spell handed down by her family, a dangerous ritual that can turn one's life force into a massive elemental... and has a high chance of being self-sacrificial, if one loses control of it for even just a moment.
[lore ramble under read more]
Originally it was a rudimental ritual spell created by the Flame Legion, one used to turn living beings into fire elementals and to animate effigies.
His warband succeeded in refining it further, but Leonis Sootflair, Ardea's grandsire, found a way not only to use it on himself to create an elemental extension of his will, but to do so without consuming his life force completely.
Others tried to emulate him, but he was the only shaman who did not burn away in the attempt, thanks to his particular talent with elementals.
Tasked by superiors to develop it into a stronger and safer-to-use spell for the war, Leonis made it a point not to reveal exactly how the ritual worked to anyone due to the objective danger posed by it (and because he preferred to keep it for himself), but he still taught it to his four cubs as a contingency for their plans to escape.
After his attempted escape and demise, the survivors of the Soot warband and other powerful shamans were able to eventually rediscover what the ritual entailed, and while they could never recreate it exactly, that knowledge was used as one of the starting points for many rituals later used by the Flame Legion (lots of those seen in-game, with Baelfire's godform being the most refined evolution of it, but also Drakin Cinderspire's boss fight for a messier but effective result).
Only three charr were ever able to complete the ritual.
Leonis was obviously one of them, and did so many times.
Still, despite able to withstand the rituals in normal conditions, he chose to fully consume himself and transform into a massive elemental of solid fire to buy time for his escaping cubs.
A display of power not even his warband expected, but that still ended with his ashes being scattered to the wind, along with those of the many he took down with himself that day.
Out of the cubs, Sidra fell to an arrow as they were fleeing, while Darion got to successfully complete the ritual, albeit for a brief time. His fatal wounds had weakened him, but in spite of it he was able to kill a couple of pursuers before his flame fizzled out.
Levant, the only one of the four cubs who wasn't there when his family was forced to flee, had make his life a lie to survive. He was never involved with his sire's plans, he denied any knowledge about the ritual, and he justified his time spent with them and his brother's transformation as cruel experimentations Leonis did on his cubs. He eventually became a powerful shaman in his own right and did much against Flame from the inside, but he died without ever using the ritual.
And then there was Cassia, saved by Darion when he shoved her into a river and later found in Blood Legion territory.
The trauma of her past prevented her from using the ritual, the only attempt she made frightening her more than death, but she figured her cubs could make use of it, going out in a blaze of glory while saving those dear to them.
And so, she carried on that "tradition" and taught it to any of her cubs that was magically inclined, and Ardea and Sidonia were the first of that list.
Ardea had not told anyone about that spell, not even Aurelia.
She just promised her warband that she'd be ready to die for them if they were ever cornered by the enemy, but only her sister knew what she meant. Sidonia's magic had ended up not being fit for rituals and that was fine by her, but Ardea's was and she had listened closely to her dam's teachings, hoping to never use it but putting her warband before herself.
In the mission that had nearly cost them their lives, Ardea was the first to go down protecting them in other ways, but 12 years later, in the mayhem and chaos of crystalline monstrosities that had erupted from the newly formed Brand, Ardea was left without choice.
Her son was in the building that had collapsed and exploded with so many next to it, her mate had just disappeared into thin air while fighting a huge Branded monster, the smell of blood and death filled the air, and the only ones she could still see standing were Sidonia, Obsius and the terrorized cubs they were protecting.
With nothing more to lose but them, Ardea told her sister and friend to run, then she chanted the ritual spell as a last ditch effort to save them.
She managed to take down one of the massive Branded griffons and any of the monsters who got close, but she could do nothing against the following wave of Branded that overran her flames and everyone left.
Ardea's transformation was powerful, far more than her grandsire's first attempts. Her body could have lasted a long time in the whirling flames, and she could have even survived, but in her grief and rage she had consumed herself and transformed into an elemental of solid flame, like Leonis had done decades prior to save his family.
In both cases, it couldn't prevent more death and loss, but also allowed their own cubs to survive.
All that was left of her was the amber amulet, lost before the transformation burned away everything, recovered by Cassia who came to the place to confirm what her daughter had done, and given to Adamas.
