Sol was startled by the intelligence of the fiend: it waited until they had come across ravaged ruins, where the frozen earth had become corrupted here and there into sickeningly-warm, toxic mire. The poisonous muck exuded a malice all its own, and when they tried to cross the mire, every pony there felt a miasma spread through them, a terrible ache spread through their minds and hearts. And before even Sol could adjust to that paranoia, that confusion, the creature had attacked.
A great and terrible black dragon had torn its way out of where it had hidden itself beneath the very earth, ripping up in a great splash of muck and mud. It had swept mercilessly into their ranks, laughing, laughing; the beast was intelligent and cruel enough to take pleasure in what it was doing, in causing destruction as its first attack alone nearly decimated their ranks.
Titan was the first to react, while Sol stared at the monster, mind trying to analyze it as her body refused to move. But her brother swept in, and met the dragon's strength with his own, catching a leg as it swept out before he slammed the great beast down on its side, then twisted - and in that single move, nearly tore the beast's leg off.
Titan was shocked himself by how easily he had damaged the creature's limb... except the dragon only laughed. It laughed, as ponies scrambled for safety, not to get into rank and formation, but only to get away while they had the chance, panicking in the poisonous bog.
And then horror only grew as the creature's limb tore completely off... but in moments, the muck and toxic sludge of the mire began to heap upwards as the shattered limb rotted away into porcelain. In moments, a new leg formed out of dark mire, quickly becoming flesh and scale, and the creature grinned.
But the true horror didn't begin until the creature spoke: it spoke, in words of terror, in words of pain and darkness, in words of the Void. It spoke, in words that made the minds of even Sol and Morgan and Titan ring with agony, before it started to chant.
Nothing could describe what happened from there: Sol was barely aware of what she was doing, as psychic pain tore through her mind, as blood ran from her ears. Her eyes blinded and bled, and she saw terrible memories, of terrible places. She saw Helheim, gaping, and she saw betrayals she did not know the truth behind. And for the first time in her life, she truly felt fear, and she truly felt helpless.
Sol, Titan, and Morgan barely escaped, broken and bloodied, escaping with less than half their army. The monster left them go, mocking them in its dark language, laughing at their pain. It had destroyed their army: it would languish in the dead and dying, it would accept the sacrifice of these soldiers to appease its hungers for now. It knew the three heroes would return after being so thoroughly bloodied and humiliated: in fact, it looked forwards to it.
For now, though, all Sol could do was lead the escape, madness wreaking havoc on her mind, pain pulsing through her body at every step. All she had learned from this encounter was that they were in no way prepared for this fight. That, and a single name that echoed through her mind:
Tyrant Wyrm.
