I know for a fact that during my prior time here, my powers were significantly less potent - and took more energy - than the equivalent spells performed by my native self. I know not if that has changed.

I believe for those named Twilight Sparkle, such limitations will be a non-issue, however.

[You don't understand, Minako. She witnessed first-hand (more or less) as Twilight pretty much reduced a fully powered Tirek to dust, tore her way INTO Tartarus to rescue her and her sister, and created a castle out of little more than the Elements of Harmony and the power of friendship.

Even the power of four alicorns combined wouldn't normally be able to do that. Whatever forces Twilight commands, she makes the other Princesses look like common unicorns.]