A moment from my anthro MLP sword & sorcery dreamscape. The infantry squinted into the darkness and swirling fog. They searched for where the next attack would come. The air was still and the fog dampened any sound around them, further enhancing the feeling of isolation and despair.
Their square still held, but everypony knew they couldn’t stay here forever. Slowly thru continuous hit and run attacks their numbers were being whittled down, but if they attempted to move in this darkness and fog they knew they’d become disoriented, lost, and then picked off one by one.
So they held their formation and desperately hoped that eventually the dawn’s light would start driving this darkness away and begin to burn off this cursed fog. However several ponies were muttering under their breath that dawn should’ve been a couple of hours ago. This darkness was the result of some dark sorcery. Al-Conikkrall and his lich commanders. Their power were apparently growing.
It had been awhile since the last attack. The archers at the center of the square had carefully sallied forth in small numbers to retrieve enemy arrows that had landed close around them. Although fog greatly limited their ability to see targets they’d still been able to blunt the enemy’s attacks on multiple occasions, but with every attack left their quivers more and more empty.
The forces of the great lich didn’t seem to have the same supply issues when it came to arrows. Periodically they’d harried the Equestrian forces with seemingly random salvos of arrows that would come whistling out of the fog. Often these salvos failed to hit anypony or struck harmlessly against the shields of the spear ponies, but slowly random arrows were taking their toll. Worse fed the growing sense of frustration and desperation in the ranks.
The officers and sergeants of this battered company were constantly moving up and down the lines of square giving words of encouragement and the need to hold the square. The square would hold. The square must hold. They were soldiers of Equestria. The dawn would come. The power of Royal Sisters would vanquish this magic. They’d made it this far. They’d make to safety. They would not fall. The 12th company would not fall this day!
They were all that was left of the garrison that had held one of the border strongholds. Couriers had arrived from Canterlot 4 days before with grim news. A massive force of undead was heading their way. More than than they stronghold could withstand. Royal forces were advancing way but they wouldn’t arrive in time. Besides the stronghold had been located on a particularly vulnerable salient of the front. The Royal Sister sought to shorten the front line and consolidate their forces. So the forces were ordered to withdraw immediately after they’d destroyed what they could of the stronghold.
And so 3 days ago they’d marched away from a rising column smoke. The stronghold they’d know as home for the last couple of years. Now it burned like some great bonfire. They traveled light. Taking only what they could carry on their backs and still keep the pace they had to maintain to stay ahead of Al-Connikkrall’s hideous forces. For soldiers of the 12th company this march had been like some slowly unfolding nightmare they couldn’t wake up from. Constantly pursued and hunted by great lich’s scouts and hunters. Only able to get the briefest amounts of sleep and rest before once again having to flee from the relentless pursuit of their foe.
Slowly this continuous march had started to take it’s toll. Any who fell or couldn’t keep up had to be left behind. No time bury their dead or treat the wounded who couldn’t keep up. Worse still was the frantic requests of those being left behind to be killed and burned by their comrades in the desperate hope it would keep them from being turned into undead who’d then hunt their comrades down. But their was no time. They had to keep moving.

Finally the exhaustion became too much and the stop for at least a few hours of rest. It had been hoped they’d gain enough distance to have shaken off their pursuers. However only few hours after the order to stop had been given they’d once again had come under attack and had formed the square they now found themselves in.
From the swirling mist was the sounds of guttural growls and groans. The ranks tighten up again. Another assault on their square was about happen, but as they searched for the silhouettes emerging from the mist they felt something. Gentle at first but growing stronger by the second. A steady breeze from the east; and as the wind grew in intensity they could sense something else. The growing warm light of the morning sun.

Suddenly great gust came tearing across the plains driving fog away. Before them on the west side of their square they beheld the terrible force of undead charging toward them, but from the east they saw something caused a cheer in their ranks. Squadrons of pegasus ponies driving away the fog and mist and one other pony.

Flying at the front of these forces was none other than Co-Ruler of their beloved realm Princess Celestia. Her mane and coat seemed to glow with its own radiant light. The ranks of undead faltered in their headlong charge at sight of the princess, but their archers still unleashed a great volley of arrows at the ponies.

Celestia dove in front of the square and raised her shield. A great light erupted from the symbol of her office and the plunging arrows burst into flames and then harmless ash. Landing of the 12th she faced the enemy before her. Raising her spear over her head she spoke with a voice like thunder.

“SOLDIERS OF THE 12TH! PRAISE TO YOU FOR YOUR COURAGE AND DISCIPLINE! NO LONGER MUST YOU FLEE FROM YOUR TORMENTORS! NOW IS YOUR TIME TO AVENGE THOSE OF YOUR RANKS WHO’VE FALLEN AT THE HANDS OF THE GREAT LICH AND HIS FORCES! THE LIGHT OF THIS DAWN WILL BE THE LIGHT OF YOUR VICTORY!”
As Celestia spoke a great cheer could be heard coming from the East. With the sun behind them came marching forward the vanguard of the 7th Legion. Sensing the tide of battle was changing the officers of the 12th order their forces to break the square and form a line 3 ranks deep. Exhaustion seemed to fade away from them in the light of the Princess and her sun that washed over them.
For the undead forces they began to hesitate and falter. The light of Celestia’s sun stung them and robbed them of the strength and courage. They now milled around in a great mass unsure what to do in the face of this new, great foe. They’d lost the initiative.
Slowly Celestia advanced on them. Her eyes began to glow white and her body began to emit brilliant blue aura which flowed from her like mist. The blade of her spear began glowing a similar brilliant bright blue. Suddenly she swung her spear in a wide horizontal arc. A thin, brilliant shaft blinding white light shot from the tip of the spear and slammed into the undead vaporizing the first 4 ranks of them and sending many more reeling back. Screaming in agony as their garments, gear, and even their flesh burst into flames.
The pale alicorn then pointed her spear at the undead host and roared. “FORWARD!” The 12th company responded with their own cheer and then advanced in tight ranks on the enemy.