In the library (rebuilt since Tirek attacked Equestria and destroyed the first one), you stood before Princess Twilight, your teacher of the martial and esoteric.
“Okay, my little apprentice, this is the time for all of that studying to pay off.”
“Yes, miss Twilight! I've been waiting for this moment!” you exclaimed.
“That's the spirit!”
You had studied for a few weeks under the Alicorn Princess. And now... it was time for your very first major spell. It was just levitation, true, but it wasn't just a pencil or the pages of a book or a broom. THIS was for real!
“You remember what i taught you, right?” she said, cocking an eyebrow
“How could i forget!”
“Now remember, the first time you cast a major spell it unlocks your internal mana font. This is why many unicorn colts and fillies have such trouble casting a spell, yet they can activate their horn to cast light. This influx could cause you to have a Mana Flare, like I did when I cast my first spell. If your body and mind aren't prepared for it, you could be destroyed! Every Unicorn goes through something like this at some point. Of varying intensities, of course”
Ever since then you'd been training for this very time, in both mind and body, ensuring that you'd be ready for this.
“I remember. I won't let you down, miss Twilight!”
“I'm sure you won't, my little Pony.” she said, with a little smirk.
Just getting her confidence in you was enough to make you pumped for what was to come.
With that she got out a series of seven crystals and several weights of varying sizes.
“You remember what these do, right?”
“Yes miss Twilight! The crystals are supposed to protect the environs, and the smaller weights will help me warm up!”
“Precisely! Naturally, you're still young, so this many should do.” she said, grinning. “Now, even Unicorns- who haven't unlocked their fonts can levitate objects of 'small weight'. Lifting something heavier requires more effort.”
“We've been over this, miss Twilight!” you said, chuckling.
“Of course, of course.” she said, with a tinge of embarrassment, while arranging the crystals and placing the weights before you.
“Okay, try the kilogram weight, to start.”
You long ago figured out that your magic casting was like button combinations from a video game. You closed your eyes, focusing on the weight. Sparks flew from your horn as the object was surrounded in an aura the same colour as your eyes. Forward, Forward, Up! It lifted slowly into the air.
“Good! Good! Now try the 2."
Dropping the first one, you repeated the process. Forward, Forward, Up! The 20 kilo weight moved slowly upward.
“Excellent! And now... the 5. Okay, now the 10. You're doing great! Now, the 20.”
As the weight you lifted ever increased, you could feel it all coming to a head. Yours! Adrenaline pumped through your veins as you looked to the next weight determinedly. This was it, the moment of truth! You could fairly taste it.
You focused on the next weight, willing it to rise. Froward, forward... up! But... nothing. It didn't move at all. You tried again, I SAID forward, forward... UP! but all it did was move slightly. You decided that this time you'd go all out. Forward, Forward, Forward, Forward... UP!
The weight lifted into the air a little. You could feel energy pushing through your veins like little snakes, slithering through your blood, then to your horn. Something in your body was starting to crack. You could feel the energy flowing into your horn, your determination to please your teacher spurring it on. Something was going to have to give, either you or the weight, and you would be damned if you'd go down!
Suddenly, that block hindering your invisible source inside you started to crack. More energy moved through your horn, more quickly, now. Sparks were flying from it. This was more weight than you ever lifted before! More than most have lifted before!
“Yes! Yes! You're doing it!” your teacher said, spurring you on to lift it higher.
Then suddenly... that plug dissolved and a wave of magic spread through you, a wave of intense pleasure coming with it. The twin energies flowing through you like wildfire. It was like having fire and ice in your veins simultaneously; Both soothing and searing.
As they say, your proverbial magical cherry had been popped, though you never understood that reference before.
Unbeknownst to you, the other weights lifted as well, including the weight next to the one you were attempting!
“Wait! STOP! that's enough!” your teacher called.
But you couldn't stop. The power in your horn was overflowing, forcing you to use it. Eventually the irresistible force overcame you and you expelled the energy. The released magic manifested as a thunderstorm, and at its center was you, rendered entirely helpless by this point.
The miniature storm crackled and sparked, breaking Twilight's shield crystals one by one.
Crack!
You knew that to contain this energy. You had to fight it!
Crack! Crack!
Moments like this define us. Moments where you have to fight with everything you have, possibly more, because any less just wouldn't get the job done.
With a conscious effort, you forced the energies pulsing in you to fuse, linking them and slowing the storm.
Crack!
It wasn't enough! You had to fight harder! You were afraid, afraid of being destroyed, afraid of hurting your mentor. Or worse, letting her down! Nevertheless, you forced yourself to keep concentrating, to keep pouring your very essence into your concentration. You HAD to stop this!
Crack!
With the last of your physical energy, you pulled the storm within yourself. It burned like fire, but you forced it to anyway. Suddenly, it was over and you fell to the floor. In a way you had never felt more energized, but in another you never felt more exhausted. You looked up to your mentor.
“D-did... did i pass?”
She smiled back down at you. “Yes, little one. You did. And look!” she pointed to your flank. Sure enough, there was your Cutie Mark! A lightning bolt in a bubble.
“If you can cast a spell of that magnitude, have a Mana Flare, bring it into you, sync with it and gain your Cutie Mark in one day... you are somepony i want on my side!”
With that you fell asleep.
Twilight brought you to the guest bedroom, putting you in the bed and tucking you in.
“Rest now, my little Pony. Tomorrow, we move to level three.”