There are subjectives, and then there are these. While you may believe a work fits here, and you might be right, people tend to have rather vocal, differing opinions about this subject. Please keep these off of the work's page.
Dethroning Moment: WarCraft
Level 1 or Level 90. Casual Grinder or Hardcore Raider. RTS or MMO. It doesn't matter. You are not prepared for these moments!
Keep in mind:
Sign your entries
One moment per game to a troper, if multiple entries are signed to the same troper the more recent one will be cut.
Moments only, no "just everything he said," or "The entire game" entries.
No contesting entries. This is subjective, the entry is their opinion.
No natter. As above, anything contesting an entry will be cut, and anything that's just contributing more can be made its own entry.
Monsund: World of Warcraft: Cataclysm probably has the ultimate Dethroning Moment Of Suck for Thrall. He's just teamed up with the player and a wily goblin called Sassy to defeat their former traitorous Trade Prince Gallywix. What does Thrall do after defeating him, make him racial leader again! This is after Gallywix betrayed the player twice, enslaved his own goblins in an abusive mine, teamed up with pirates, and right after he personally tried to kill Thrall and the player. Worse is that the player and Thrall killed tons of mooks to get to Gallywix and other goblins such as Sassy showed themselves to far more capable and caring then Gallywix. This moment totally derailed Thrall into a caricature that no no longer resembles his old self.
MiltiadesBooga: Further to the World of Warcraft example above - what in the sassy Francis with the derailing of Kael'thas and Illidan in Burning Crusade!? Wrath of the Lich King seduced me back to the fold (fist shaking goes here) but that little bit of WTF had me trying to throttle my keyboard. Blizzard, please don't let people who have never played WCIII write scenarios involving characters from WCIII.
CombatLibrarian: I found the entirety of the Goblin starter area to be a dethroning moment of suck. Let's see...for the first time ever in WoW, your character is given a canonical sexual orientation (straight). I tried to engage in some proactive suspension of disbelief ("Um...okay, my character is culturally being forced towards having a relationship with a guy but she doesn't like! Yeah, that's it...") Only to find that after the game-appointed S.O. leaves my character, my character is so overcome with jealous rage that she killed him, ripped the still-beating heart from his chest (I'm quoting), and then killed the goblin woman he left me for. It's worth noting that unlike all previous races, the Goblin and Worgen starter zones are completely unskippable and MUST be completed to progress to the rest of the game. Combined with the bizarre Fanon Discontinuity of making every single goblin player character the previous "next up and coming trade princess/prince", the entire goblin starter area was a WallBanger that I decided was a hallucination brought on by Kaja-Cola overdose.
Valkir: Another one from Cataclysm. Not the overall appointment of Garrosh Hellscream, but rather the precise moment they show it in the pre-event. He's suddenly a humble guy that wants what's best for the Horde and is being respectful to everyone. He says things and acts in ways that are radically inconsistent with his previous characterization in Wrath purely for the sake of revisionist history so Blizzard can force him down the player's throat. This moment specifically sets the tone for all future encounters with Garrosh, because it's nothing but shilling the Creator's Pet from there on out, with him suddenly being a competent badass due to events in Northrend that we as a player never got to see. Garrosh Hellscream, you made me, a fan of Warcraft for over 10 years and a hardcore raider, quit the god damn game.
Regu: A minor one from Cataclysm, but one that still made me mad. In the expansion, the Deadmines were completely re-done and even had a storyline in Westfall to explain. After discovering that the daughter of the former end boss has been reviving the Defias Brotherhood, you are sent in to defeat them. After running through an entire dungeon with completely new bosses, you fight the end boss. Oh but's not who you think it is, it's Cookie, you know that murloc who wasn't even required to down for completion. You can only fight Vanessa in the Heroic version. It's a complete and utter waste of time, and a crappy "twist" to boot.
PyroWildcat: The "Elemental Bonds" questline, full stop. This thing takes one of the longer-running plotlines in Warcraft lore, the festering hatred Fandral Staghelm had for both Malfurion Stormrage and the Dragon Aspects, one that had been ongoing for several years in real time, and a few millenia in-game, and completely shunts it aside to give Thrall center stage. And then both Alliance and Horde are "treated" to a long, obnoxious, overblown, irritating, and downright nauseating love letter from the developers to how "awesome" Thrall is. And, since Chris Metzen is so butthurt over the Fan Preferred Pairing for his little Thrall, we also get to hear over and over again about how awesome the utterly one-note characterAggra is, and how she and Thrall luurve each other so much. Oh, and the player is brought into this travesty under the pretext that they were going to witness the Cenarion Circle, the Earthen Ring, and the Dragon Aspects working together to restore the World Tree. What comes of this? Nothing! Apparently, the developers thought that Thrall's wedding was more important. To get an idea of how bad this was, this quest line was enough that even many of Thrall's own fans were sick of him afterwards.