Firebrand making a temporary Heel-Face Turn in INTERCEPTION. Not only does he hold off the Observer and prevent him from taking Noah, but he also gives Noah valuable clues that could save his life and win him the war. The Observer gets PISSED over losing control of the situation. A comment on YouTube sums it all up perfectly: U Mad Observer?
Note that this is the only time the Observer has ever lost control (both of his transmissions AND his emotions).
Firebrand also manages, in just a few short sentences, to expose the Observer for the liar he is: the Observer had previously stated that the Administrator has total control over the Collective; clearly, that's not the case.
A meta one for Adam, the creator of the series. "The Live Stream Incident" shows that Noah is both Firebrand and had gone back in time, inadvertently causing several events of the past. One of them was delivering the rubber eyeball found in "The Device" to his own closet, whilst screaming "Oh my God! It's me! Noah!" And sure enough, when the fandom went back to check the "Device" video, they could make out the same words faintly in the noise from the closet. So Adam managed to plan ahead for a reveal that would take over a year to pull off, and to surprise the fandom that went over his videos with a fine-toothed comb looking for clues. That is awesome.
Firebrand deserves credit for his actions in Interception and during the 11-11-12 Livestream. First, he stepped in and publically declared that he was on Noah's side against the Collective, preventing the Operator from taking and brainwashing Noah. Then, in the Livestream, we learn that Firebrand sent Noah back through time twice to not only prevent his abduction, but to ensure a stable time loop involving the rubber ball and Noah's first sighting of Firebrand. Then, at the end, after Noah tearfully records himself saying "Thank you," Firebrand replies at the end by posing like a boss with the message "You're Fucking Welcome." Bad. Ass.
Hell, Firebrand gets points just for retaining so much of his human personality in the first place. We don't know exactly what happens when someone joins the Collective, but based on what we've seen, itcan'tbepleasant. And after all that, not only has Firebrand held on to some semblance of humanity (enough so that he remembers what it is to be human), but he still has enough free will to rebel against the machinations of both Slendy and the Collective — which, in case you've forgotten, is a Hive Mind. No wonder they call him "The Stubborn".
Firebrand Flipping the Bird to The Administrator, a.k.a. Slendy himself. And all Tall, Dark and Faceless can do is tilt his head in confusion/surprise.
Considering he's just been freed from The Administrator's control, one can imagine he's been waiting ages to do that, which makes it even better.
Extraordinary Circumstances is nothing but this: After Noah opens the briefcase, he discovers a plethora of new items, including the journal, some tapes of Milo... and a giant fuck ton of cash. Just after discovering said wad, good ol' Firebrand pops out and congratulates Noah on opening the briefcase. As brief as it seems, Firebrand just seems so proud of Noah that you can hear it in his voice.
In Bridge to Nowhere, Noah finds said bridge while traversing a fucked up "spirit world" version of New Jersey, and meets Jeff, who tells Noah to kill himself rather than listen to Firebrand or HABIT. Speak of the Devil, HABIT shows up to talk to Noah about what Jeff told him, stating that Noah doesn't have the guts to do anything except follow his orders; in response, Noah gives what is likely the best Shut Up, Hannibal! in Slenderverse history:
Even better? When HABIT starts to mock Noah's reaction, just as he did with Jeff (who uttered something similar just before he was tortured in "Colon D"), Noah has an answer ready: "It makes me feel better. I derive pleasure from that. Fuck you." HABIT's response suggests that this might be the only time someone's actually given him a reason for why they said it.