@Meanlucario
I mean, seriously, it wasn’t just the fact that Starlight wasn’t being angry after literally bottling it up, draining it… she was behaving
lethargically overall, drained of emotions in general… almost like how depression might be like to experience.
Well, I’ve always found magic is tied to my emotions. Whatever I’m feeling fuels whatever I’m doing, and the stronger I’m feeling, the stronger the magic.
(As you said, she didn’t say it had to be anger, and it does generally work as a general rule, regarding emotions; if Twilight Sparkle is being determined, her spirits high, she can successfully fight against Sombra, if she’s determined and quite pissed off, she can make “3rd Form Tirek” lose a tooth where Star Swirl failed to leave a scratch; and as cliche as it may be, the tactic of “if you can make them not believe in themselves through fear, they can’t win” is tried and true. Also, dark magic would quite plausibly go hand-in-hand with emotions as well, the negative ones. and no, sorry theorists, “alicorn magic = dark magic” was never having anything point to it outside of Twilight’s aura looking like it exactly once or twice over the course of one two-parter in S4, so having that factor into anything other than an AU is… probably a stretch, isn’t it?)