Widdershins

But I didnt see her manipulate anything. I saw others make their own choices and her claim it was her plan after. I saw her only knowing ehat to fo after a bigger villain told her.

 I feel you could have cut her entirely and everything still would have gone down.

I can't tell what the last season is. Netflix kinda did a thing where they split up a season and called it different seasons. Nine was the last season? The one that ended with... uh, Tirek never leaving his cage and the main six getting locked in a room because they didn't check the door before it closed... and Starlight somehow walked into an obvious bomb created by a four-year-old that somehow managed to endanger all the power in the land despite the fact no natural rules being capable of falling apart from a single point like that... was season Eight?

... That two parter made no sense to me.

But what I was seeing instead, in that two-parter... was that everypony else just got stupid to the point of being barely functionable just so they could write a filly as a villain.

 None of those decisions have to be made. Abandoning the whole of the school they founded for them all to go off to the same place and leaving behidn what needed to be defended. Tirek, a guy who darn near ATE Equestria whole, was apparently not guarded, just thrown into a cell where anypony could come talk to him. Tartarus was just some cave with a magical lock on it. Starlight apparently walked into a ball of energy and stood gaping at it despite her being even more acquainted with magic than Twilight is. RD, Miss "Ten Seconds Flat", apparently not capable of dealing with a sudden downpour.

 Everything has to go just right for Cozy Glow. She didn't even know how to pull magic in herself. She basically had to have somebeing else do all the work, write it down and she just gathered all that was needed. Apparently pulling out one string dooms Equestria's fickle laws of reality. Apparently the super powerful artifacts of numerous royal lineages are just free to lend out to any school that asks, and some four year old filly can just steal them out from under adults that have saved the world and fought battles. That any student of magic can do the research from some random book in a public library to know that these artifacts can doom the world if put together... and nobeing takes any precautions at all.

 It's almost as egregious as the Changling Throne episode.

 Where Chrysalis somehow claims Three kingdoms, simultaneously, in the same night, kingdoms she's had very poor history of attempting to conquer... all because she now has a McGuffin rock that she's apparently had all along. A device that can somehow mitigate fully, even from a distance.... Discord. A God of Magic and more force of reality-bending than a living creature. 

MLP, in its last seasons seems to be only capable of crippling everything pre-existing just to try and up ante. It's saddening.