Early on, there are moments where you might feel like Brolli can possibly change, such as Marisa and Patcholi finding out that one of his abilities is "self-awareness", and some of his actions arguably show this, such as eventually seeming to genuinely care about Reisen. Too bad what follows cannot be avoided.
In episode 11. Marisa punches Brolli, when he badmouthed Reimu and claimed that Marisa hated her, stating that even if she is her rival, Reimu is also her best friend. And that even with her selfish tendencies, Marisa would give her life to protect the balance of Gensokyo. Also doubles as a Crowning Moment Of Awesome.
In episode 12. Brolli thanks Nitori for all the help she has given him and hugs her. He even refuses Lepus advice to take advantage of her when she is emotionally vulnerable.
Doubling as an Awesome Moment, when everyone wants to kill Brolli when it turns out that is what will resolve the incident, Reimu of all people is the one to tell everyone to stop, thus proving that even though Reimu can be a bitch and she may hate Gappies, she is still the protector of Gensokyo and its people.
Momiji, who hates Aya, is willing to save her if it means defeating Tenshi. Even though it gets Brolli killed as a result, Momiji admits she just wanted to do the right thing, facing dishonorable discharge with Aya.
The truth behind Tenshi's incident: she did it to Mercy Kill Brolli before the rest of Gensokyo could stab him in the back, simultaneously dragging the rest of his enemies across the Moral Event Horizon with her via a Zero Approval Gambit. And the best part? There's nothing anyone can do to get revenge on Tenshi without blowing their cover.
Tenshi: I wanted Brolli to die fighting someone he could hate, not get stabbed in the back by someone he loved...
For all of the dark elements of the ending, Mokou and Kaguya's survival and gleefully continuing their duels gets cheers from the Ustream audience.
Despite making a movie to ruthlessly tear down Colonel Diamondback's videos, Spaztique and Colonel Diamondback ended up not just becoming friends, but the two ended up introducing eachother to the rest of the Walfas community, who now have a doujin group together. Furthermore, some of the people who've been watching Diamond In The Rough's previews are now hanging out with the real Diamondback and Spaztique.
During production of Episode 13, the entire Ustream and Raidcall audience cheered on Flandre during her battle with the Diamondback beasts.
MindOFCorruption97 gives Flandre bombs
DeityDiz93: I so badly want Flandre to win, even though I know she won't...
The voice chat helped co-op an alternate final shot for the ending. Instead of Brolli just staring into the light, wondering, "Who am I?", Komachi hugs Brolli and tells him, for his bravery to sacrifice himself to save Gensokyo and end the Gappy era, "You are different." The final shots fades to white on Komachi hugging Brolli.