It feels like you can see a progression in power throughout this episode.. She starts with small things like altering the spellbook itself, her fainting couch. Then she moves to changing bigger things - apple carts, buildings, the road system, and can spawn smaller objects like a crystal armor or a dress. And at the end, she can alter multiple objects with ONE magical outburst and conjure up several Rariots. I wonder if Spike had hesitated longer, would the spell get such a strong hold on her brain it would refuse to release her?

@toonbat  
Rariot!

@SeraphimDawn  
Chariot Race, or Rariot chase?

If dark magic can create ex nihilo and normal magic can’t, you can start to see the temptation to use it regularly.

And I began to think, that she just pastes those things to spam.

Chariot Race!

Ok, so she has the powers of God now…

@misnamed  
Out of nothing? Of course not! This is where all the ice cream she ate is going.

Rarity will take over all of Equestria with her army of Rariots!

Out of all the puns in this show, somehow this is the one that hurts the most.

@PonyPon  
But the side effect wasn’t much. When it was all over she was instantly back to her older self, she didn’t need to recover from that magic spree of hers. Twilight showed how excessive use of magic puts physical strain on her, Rari experienced nothing like this after overuse of this powerful spell that even Twilight can’t do.
 
It was much the same as Alicorn Amulet in a way. It’s one thing when the user doesn’t feel the strain while their mind is affected, but they should certainly feel it after coming back to their senses.

@Background Pony #87D6  
It does.
 
For the brain.

You’d think using such incredible power should take a toll on the user.

@misnamed  
YES
 
unfortunately, instead of an overpowered sexy godess rarity, we’ll probably get some one time forgetable villain of the day, or worse, none at all.

@A Sad Pony  
Seriously! I almost wish the issue hadn’t been so quickly resolved. This could have been a doomsday crisis worthy of a season finale.

@misnamed  
This can only lead to something usually found in epic mecha anime, like Getter Emperor expanding until it fills the universe, or the fabled Spiral Nemesis from Tengen Toppa Gurren Lagann.
 
Some powerful cosmic force will try to stop Rarity from filling the universe with hats.

She’s creating things out of nothing! Eat that, conservation of mass! The laws of physics are meaningless!

Looks like Rarity found the Chariot cheat

Pimpin’ my chariot

@A Sad Pony  
she is turning into discord.

Also, she apparently has the power of creation ex nihilo.