I landed on one knee on a stone platform as I materialized at my destination: the Void.

What is this, Mega Man?
I

I landed on one knee on a stone platform as I materialized at my destination: the Void.

Drayke materialized at his Final Destination.
II

In the distance, I could see what resembled swirling galaxies and all sorts of strange, twisting lights, like some kind of bad acid trip.

https://www.youtube.com/watch?v=V9bPD50SGeg
I expect the Shattered Dimensions Smash Bros. crossover soon, Rawg.
III

“Well, we made it!” I turned to see Cadence standing on a slightly higher boulder behind me. “Now what?”
I looked around and saw a massive platform somewhere in the distance, much larger than all of the others and surrounded by a wall; the thing looked kind of like a coliseum. “I’d check there,” I said, pointing towards the structure. “If I were an evil overlord, and I was for a while, I’d be waiting in there.”

You have to get through the Great Maze first, Drayke.
IV

Cadence nodded in agreement and leaped down to join me on my rock. “Where’s Spike?” she asked, looking around in confusion.

That's... actually a good question. Where is he?

Just then, I heard a strange ‘poof’ sound, and Spike hit the ground in front of me.
“Ready to help,” he mumbled, dazed, before jumping up and shaking his head. “So, what’s the plan?”

Ah! Here he is, and just in time for comedic relief!
V

Is the mighty human warlord actually concerned about something?” she asked teasingly. Hearing this, the others all started watching Allen’s movements closely.

Oh! They woke up. I was beginning to think they never would!
VI

As he spoke, several crystal spikes slowly materialized along the walls of the coliseum, each one shifting and twisting until it had the form of a Crystal Sentinel. Once they had fully formed, each one leaped from its spot and began to trek across the empty space to meet their target.

Summoning more minions won't help you, you scrub. Has being the antagonist of this story once already taught you nothing?
VII

Princess Celestia laughed. “You fool; the Sentinels are nothing against a wielder of magic, and Drayke had a crystal that has the potential to match even my power,” she called out angrily.

Yeah, and look where that got you.
VIII

Rarity perked her ears up. “Girls, do you feel that?” she said, her eyes suddenly brimming with hope.

I'm just gonna go into this corner over here and laugh my eyes out.
IX

“I think you may have overestimated your abilities, Sanguis,” Luna said wisely, “because I think Drayke may have an asset you didn’t think he would get his hands on.”

The favour of Rawg.
X

Allen stared at the ponies in confusion. “What is it?” he demanded, “What does he-” he suddenly stopped, his eyes growing uncertain for a moment. “No,” he breathed,

No.
XI

There's a lot of bullsh*t fighting, so I'm adding one sin in case I missed something.
XII

"What the fuck is that?” I cried when I saw the massive thing forming on a massive rock plain several yards away from us; it looked like a giant mass of crystals had suddenly appeared and were mashed together wherever they would fit

Sanguis' compensation for something.
XIII

I held the Sword of Harmony near them, and they flew into the slot on the hilt one by one until they were united into a single, white gem, just as I had seen in Argentum’s memories.

Congrats, your Rapier has become a Noble Rapier, King Marth! I know, I know. Rapiers don't become Noble Rapiers in Fire Emblem.
XIV

“Alright, you overgrown asshole, take this!” I cried as I slashed downward towards my enemy, and a wave of rainbow-hued energy blasted the creature and ripped one of its arms off.

Rainbows.
XV

The creature stopped for a moment and looked at its severed arm as the limb disintegrated, and then the jagged shoulder began to jut out as a mass of crystals grew out from it.

So this guy is basically the Bouldergheist from Super Mario Galaxy.
XVI

Cadence stamped a hoof. “We don’t have time for this!” she yelled, and I quickly ran and swung one leg over the armored alicorn, straddling her like… well, like a horse.

Okay. Carry on. I'll just be laughing again.
XVII

I grinned dangerously. “At the risk of you refusing, I’m going to refrain from revealing the details of my plan. Just get me directly above that thing!”

How this works is beyond me.
XVIII

"Let’s hope this works!” I yelled as the wind rushed past me, and I flew past the protective crystals and struck the core of the beast dead-on, ripping it out with me as I hit the ground and rolled for several yards. I stood up as the creature let out a rumbling roar and fell to the ground, breaking into pieces that slowly turned to dust. I saw Cadence land a few feet away, her visor folding away as a look of relief crossed her face.

This also works.
XIX

Cadence nodded as we parted, and turned to the coliseum. “Let’s go; we still have one more fight ahead of us,” she said grimly, and we quickly headed for our final destination.

https://www.youtube.com/watch?v=V9bPD50SGeg

...

Again.
XX

Total Sin Talley: Twenty
Sentence: Final Destination

5395559 I just googled it and, well, pretty much. But walls.