@Background Pony #B736  
I think Teleportation is a spell taught at celestias School. Celestia also teleports, and Sunset Shimmer was Twilights predecessor and she can use it as well.
 
“copying” spells seems to require one to have a Basic understanding of how it functions.
 
During the Season 5 finale, Twilight uses the time-spell, Starlight modified, several times. But even though she used it several times in a row, she was implied to be still incapable of casting it without the scroll, since she had no idea, how starlights modifications worked, otherwise starlights threat of tearing up the scroll would have been pointless.

This is distressingly plausible.
 
@Aperture  
Twilight’s been copying spells she sees since the pilot when she copied Nightmare Moon’s teleport spell.

@ARandomByStander  
No, she cant do that. People assume that, because of the Season 3 premiere, but i believe, that she knew the dark spell, before celestia showed it to her. After all, that spell only Projects an Emotion on something. Celestia only showed Twilight, how the Crystals of the empire react to certain emotions. positive emotions like hope and love, make them shiny, while negative emotions like hatred and fear make them black and spiky. when Twilight realized, that the Castle might have had a different layout while under sombras controll, she just performed a Basic Emotion projection spell.
 
After all, she knew how to manipulate emotions in lesson Zero.

@TheCrimsonFreak  
The Mean Six were autonomous golems.

@TheCrimsonFreak  
Who said they had souls?

Wait…so are the Mean Six’s souls trapped within the tree, begging for release?

@ARandomByStander  
Like Kenshiro or Shishio? X3

Isn’t twilight’s power to recreate a spell after seeing it once?

@FanOfMostEverything  
He was still better than X though. X ended up offending the whole Dragon race by implying that violence is always evil no matter what, at best only ever being a necessary evil.

@Darth Sonic  
Twilight had mixed feelings about giving Mega Man that guest lecture spot.

“Remember students! Friendship is magic and thus weaponizable, and murder gives you new abilities!”

The implication here being that it appeared in Twilight’s form, specifically, because it gained that form after it consumed Twilight’s clone.

@Derpyfan  
When someone makes lemonade does not use all the lemon. He just squeezes it out until he gets the juice he needs.

The reason this theory doesn’t work is because it didn’t absorb them, it turned them into wood.

That’s… horrifyingly compelling.

…This theory would put “You ruined everything!” being Evil!Twilight’s last words in a new light.

That’s dark and awesome at the same time.

“That didn’t work out at all like I’d hoped.”  
-Chrysalis, probably.