Pointing out a mistake: The dragon in the bottom panel is supposed to be Rockjaw, the blue-gray one seen in later pages.

@Ertinax  
This is the author of the original fanfic speaking.  
In my own story canon, Spike’s greed-growth is unusual, even by dragon standards–Among normal dragons, greed growth is just a surge in growth rate, like puberty. being greedy makes ‘em grow up faster (but not THAT fast.) Spike’s on the other hand is a side effect of being marinated at his hatching in enough transformative magic to turn a mountain into mozzarella.  
The villain dragons had to boost their growth by devouring masses of Equestrian fire opals, which magically boosted their size. Spike didn’t have to.
 
As to the fire— he’s still getting control of it. He sincerely thought he was incinerating them, because he didn’t realize he was spraying them with fax-fire. (the message spell was out of wack due to his rather sudden size change.) It IS, however, reversing their Greed Growth, by the expedient of NOT teleporting the fire opals in their stomach….

I like my dragon extra crispy

@Spiked Punch Here’s the thing: Spike honestly doesn’t know that his fire in this case is still enchanted. As far as he knows, he is LITERALLY burning them to ashes right now. That’s the only reason why he’s even USING his fire, because he honestly thinks that it’s destroying them.
 
@Ertinax @Rostam A bit of a spoiler, so don’t read if you don’t want to know: Spike’s growth IS based on greed, as his treasure horde is being threatened. The only difference is that, unlike a regular dragon’s gem and treasure based horde, Spike’s horde are all the ponies he knows and cares for, ESPECIALLY Rarity. Spike’s possessiveness over the ponies, his friends and loved ones, allows him to “greed”-growth to a large enough size so as to protect them. An example of how you can tell this is that his Greed-Growth form here is completely different from Spike’s Greed-Growth form in “Secret of my Excess”.
 
@Background Pony Those are the fire opals that the teenage dragons ate while on their way to the Crystal Empire. Apparently, fire opals are opals that have absorbed a high concentration of magic by forming in the hearts of live volcanoes. The teenage dragons ate them so as to greed-grow themselves to approximate “adult dragon” sizes.

@Spiked Punch  
Read the last chapters better, man… much of the battle is him going in swinging, forcing the jerks to adopt desperate measures.  
Those arms aren’t for cuddles, y’know.

@Background Pony  
That’s just it, I would expect him to use this technique WHEN he is a toddler.  
Using the magic fire to send the bad guys to Celestia.  
But not when he’s an adult!  
One would expect him to win his own battles by then, which he should be able to do.  
What with his fire being able to both teleport AND burn depending on the case…I would’ve liked it better if he actually defeated them himself on this scenario.
 
Sighs  
But that’s just me, and the author is free to do so any way he/she wants :)

@Spiked Punch
 
Aren’t you just happy that he becomes more than just a helpless little toddler? I mean, I know its escapism, but there’s wisdom in counting your blessings, too.

@The Neutrino  
Yes I figured with the other guy’s comment about Celestia’s warhammer.  
I know they’ll get stomped once they reach Canterlot.
 
What depresses me about it is that in this story, even after Spike grows up into his big, scary Kaiju-like self…his badass move ends up being sending the badies over to “mommy” so she can punish them instead :(

@Formido  
And Luna also joined the fun. Celestia was practically giddy with delight when the first one showed up. Namby pamby my ass.

@The Neutrino  
I think they actually got it worse by not being incinerated.

@Spiked Punch  
That’s exactly what happens. They get teleported to Celestia… to get a warhammer to the face.

@Spiked Punch  
I’m sure if he did know he’d turn it off. As it stands he’s so incredibly enraged right now that A: He didn’t think about it being on and B: All he knows is that they’re being consumed by fire then disappearing.

@Formido  
I plan to read the fic, yes…hoewever I think most people get from the pic alone that he’s trying to kill them (its quite obvious). The point however being that whatever his intention is, all the fire does is teleport them…as if, it was the only thing it could ever do.
 
Its just my opinion though, but I find that a bit depressing :(
 
I mean, its fine that he’s wingless and everything…but now his fire is harmless too?  
Good thing the ponies are trying to hammer that dragon nature out of him…because he’d get quite the inferiority complex (even after growing) if he actually TRIED to be a dragon.

@Spiked Punch  
If you’d read the fic you would know that Spike doesn’t know he’s teleporting them. He’s actually trying to kill them.

@Ertinax  
Turn greed into anger or someshit  
Greed of his lust?

Doesn’t really make sense, though.  
Spike doesn’t grow when he gets angry - he rather explicitly grows when he gets greedy.
 
Even then, if anger triggers growth, what’s to stop the other dragons from growing larger, too? Seems internally inconsistent.

@Spiked Punch  
Check the fanfic that originated this… a little spoiler: Celestia, when she was younger, used to hunt dragons with a warhammer the size of an oak tree. Those dragons are NOT out of trouble.

Time to mutilate them all!

@Spiked Punch
 
Not neccesarily. Maybe he did it uncounciously

Oh please…don’t tell me he’s teleporting them…  
The old “sending everything to Celestia” joke’s funny and all but people sometimes act as if it was all his fire could do, when in reality scrolls and a card are the only things he’s ever teleported. His fire can burn like regular fire as well, as he did with books, wood, etc.

Kudos for “fewmets,” the proper term for dragon feces.

What do you mean “nothing left”? Then what are those red things in panel 5?
 
Also “Where did he go”? Oh, you know, just decided to go visit his mother, she so rarely see’s him anymore, and a son really should visit-he just got consumed in mass of fire WHERE THE F*** DO YOU THINK HE WENT!?

YOL TOOR SHUL

 
wait a second….you are not killing them, YOU ARE TELEPORTING THEM! damn it Spike! this is not what i teached you!