Okay, so, several people have long complained about the inconsistency of Starlight, a simple unicorn, being able to go toe to toe (or is that hoof to hoof?) with an Alicorn, especially when that Alicorn is the Alicorn whom is bonded to the Element of Magic.

Well, after watching the season 5 finale and then the Bronies React to season 5 finale again last night, i have come up with a very good idea as to how to explain Starlight being so OP and it's all thanks to another show, an anime that changed the idea for Magical Girls.

Okay, here's the thing every forgets. Starlight actually tells Twilight that she'd written the spell so that it would take HER back in time, so even thought Twilight cast the spell the second time, it still brought Starlight back to that same point. This means that Starlight became a focal point in the spell as it was meant to affect her directly.

now, what does this mean to how she was so powerful?

Well, going back to that show i mentioned before, a similar thing happens. In Puella Magi Madoka Magica, Homura Akemi goes back in time SPECIFICALLY so that she can save Madoka from dying/turning into a witch. This being the case, Madoka became the centre-point to all those alternate timelines, each ending in disaster, cuasing Homura to keep redoing it to try over and over again.

what does this have to do with starlight? It's the same thing.

Starlight is now a centre-point to the time spell, meaning, every time Twilight used it, Starlight became more powerful, to the point where she was able to go toe to toe with an already drained Alicorn (remember, by the point of their fight, Twilight had cast the time travel spell several times and we know powerful spells can be draining, not to mention she just got away from a battle with changelings).

It probably has a few holes in it, but i think it's a good theory to explain why Starlight is so powerful when she's a normal unicorn.

you're thoughts?