"The third hero was an agent for the guild of rogues. Usually their job is to stealthily slip behind enemy lines and assassinate the lich coordinating an army of undead. Of course, the lich just comes back to life again, but they come back at the lich tower, and the army would be left without a coordinator.
"This time, however, this particular rogue had a rather different mission. A very important pony had run off to the lich tower on a suicide mission, and she was tasked with stopping her. And it wasn't the apprentice mage that she was after. Nopony really cared about her running off.
"The pony that this rogue was after as Crom's personal student. Supposedly. Truthfully, the rogue doubted that the fabled alicorn of war truly existed. Although Crom was supposed to be the leader of all living ponies on the planet, she had never actually seen him. Other ponies insisted that it was because Crom spent all of his time doing battle with the undead, but she suspected that the truth was that there was no alicorn of war at all. Instead, she was sure that an unseen group of ponies controlled everything from the shadows.
"The pony that she was being sent after, she assumed, was most likely a renegade member of that group.
"She had successfully infiltrated the tower of liches and was trotting along the rafters, her black cloak making her nearly invisible in the poorly lit area.
"Unfortunately, she didn't see the magical trap."
There was a spark of magic and the rogue suddenly found herself trapped inside a cage of terrible red energy.
She tried slamming her hooves against the cage, but the strange energy cage simply reflected her momentum.
"Think, Sweetie Drops!" she said. "There must be a way out of this!"
Suddenly, she heard a cackling voice from below. The cage lifted into the air and then brought her down to the floor where the laughing lich was waiting.
"I know your kind!" he said with glee. "Always sneaking about, stealing artifacts that aren't yours and stabbing us in the back. Did you really think that we would let ponies like you into the tower without some kind of a counter-measure? You ponies never learn!"
"So what happens now?" asked the rogue, refusing to let her fear show.
"Well, ordinarily we would throw you in the dungeons to rot with the other mortals where you would wait until one of us require a living subject for one of our rituals, or some such thing. However, I have a special plan for you! The others are having a death game at the arena today! I will make you fight on my behalf!"
"Death game? You expect me to kill other ponies?"
"No. Frankly, I expect you to be killed. And the other competitors are all liches. We kill each other all the time, you see. It passes the time. We've turned it into a game, of sorts. Unlike you mortals, we always come back when we die. And, just to keep things interesting, we place bets.
"But even though we always come back, getting killed isn't very pleasant. So, I have no problem with having you go instead of me, even though you will surely lose me the thirty minions I have placed as a bet.
"However, if you do somehow manage to survive, I will win a whole two hundred and forty minions! Isn't that grand?"
The rogue stayed silent.
"Well, why should I care about your opinion anyway? Come, the fight begins shortly!"
And with that, the lich magically levitated the poor caged mare alongside him and made for the tower's arena.
It wasn't long before she found herself behind a wall of bars at the edge of the arena. Her captor had still not released her from the cage.
"Now then," he began. "Just having a free for all deathmatch got pretty boring after the first few decades, so we've taken to adding special rules to the fights in order to spice them up! Any minute now, the announcer is going to declare what special rule will apply to your fight."
They didn't have to wait long.
"The next match will be..."
The announcer lich's magically enhanced voice paused for dramatic effect.
"Invisibility combat!"
There was an eerie groan of disapproval from the hundreds of liches in the audience.
"Oh, quit your fussing!" said the announcer remprimandlingly. "Every time we have a invisibility fight, I hear the same complaints! It's always 'I can't see them!' 'What's going on now?' 'It's too confusing!' 'Didn't that guy die already?' Well, just shut up and deal with it!"
"Alright, listen up," said Sweetie Drop's captor. "You have seven opponents. In this battle style, we channel the magic of the whole tower to make each and every one of the combatants completely invisible."
"How are we supposed to fight?" asked the rogue in confusion.
"Well, you see, every time you cast a spell or touch an opponent, whether on purpose or by accident, you'll turn visible again for a couple of seconds. When that happens, everypony will know where you are and will probably try to kill you. One technique that the others use all the time is to create illusions of themselves in hopes that the others will go after the decoy. You might consider doing the same."
"I can't cast spells," protested the rogue, "I'm an earth pony!"
"Oh. So you are. Imagine that. Well, good luck then, you'll need it. In just a bit, those bars will be lowered and all of the combatants will be free to attack each other, including you. See you after the match, if you live!"
She watched as the lich cast a spell and teleported away. The magic cage finally dissipated.
"I have just been informed that Callous Curmudgeon is substituting a mortal mare in his place!" said the announcer's voice. "If she is defeated, it will be for good, so the stakes are high!
"Fire up the invisibility field!"
The rogue watched in awe as her own body disappeared before her eyes.
She looked skyward and said, "Lord Crom. If you are real, then help me! And if you're not, than to Tartarus with you!"
"And... Lower the gates!" finished the announcer.
Several liches briefly flashed into existence and then began to gradually fade away again. Some of them started to shoot spells at one another.
Several magical projectiles struck an opponent, all of whom screamed and fell to the ground before disappearing.
However, one magic bolt hit a lich and he screamed and melted into the floor. He didn't disappear.
"Was Austere the first casualty just now?" asked the announcer. "I think Austere is dead. Good job, whoever's spell it was that got him."
Suddenly, another screaming lich appeared out of thin air, clutching at his back before falling over.
"Ooooh!" cried the announcer. "I'm pretty sure the mortal just knifed Quagmire in the back!"
As more of the liches fell victim to hostile spells, the arena rapidly became much less frantic.
"Does anypony have any idea who's left?" asked the announcer. "I've lost track."
One of the liches decided to try throwing fireballs in random directions. He quickly was blasted by an energy bolt from behind.
After that, the arena was silent for a long time.
"Just waiting for somepony to make a move," said the announcer in boredom. "Any day now..."
There was another scream as yet another lich collapsed to the ground.
"And the mortal just killed Putrid Pest!" cried the announcer. "He didn't even show himself! I wonder how she did it?"
The arena became inactive once again.
"Umm..." began the announcer after a while. "Is it over? Are they all dead yet? We're looking into it."
...
"Oh. The invisibility field is down, you say? Where is the mortal? Does anypony see her?"
There was murmuring from the audience.
"Oh, for evil's sake! Did she slip away? How did she get away without anypony noticing?"
"Unbeknownst to the audience, the rogue had noticed that the last lich was wearing a strange amulet. She knew that sometimes liches carry enchanted items that protected them from harm. Of course, if this amulet was an amulet of protection, it hadn't exactly done it's job, but it might still be valuable.
"She took it. It turned into another golden rod with the word 'courage' carved into it. Unseen by anypony else, the amulet flashed and she disappeared."