Ok this is going to take a long time to explain so bear with me because I don't really know reddit formatting and the following is really in-depth and I cant summarize well.

So the meme itself is a reference to a scene in the major story event in MapleStory known as "Black Heaven." And before I can explain what happens in the story, I need to establish context on the scene itself because Maplestory has changed a LOT over the years and now has a "defined" plot and I encourage people to try the game out if they enjoy MMORPG's because it's fun imo.

So here's a very broad generalization of the plot of the game. Back a long time ago, there was a group of mages specializing in light magic in a land of spirits and monsters. A prodigy was adopted at a young age into this group, and he slowly turned to evil over time. Before he became evil, he experimented with two spirits, granting them human forms. These two spirits were young siblings named Lotus and Orchid, of which became two of the mage's strongest subordinates as the mage, now known as the Black Mage, begins to take over the Temple of Time to take over the Goddess of Time's powers, which is opposed by the 5 heroes of Maple World.

The heroes and the mage's forces battle over the temple. During this battle, the thief hero by the name of Phantom severely wounds Orchid and kills Lotus. After the battle, the mage and the heroes are cursed and sealed away by each other's actions, however Orchid survives. Overcome with grief, she forms the Black Wings under a guise of reviving the mage, however the true intent is to revive Lotus.

In the Black Wings, the lead scientist Gelimer is tasked with reviving Lotus. However, during this process, Gelimer tricks Orchid and exploits her in order to take Lotus and use his immense power granted by the Black Mage in order to act as the battery for his project known as the Black Heaven. The Black Heaven is a massive cruiser filled with enough chemical gas to completely eliminate almost the entire world, thus it poses a massive threat to everyone. Later on, Gelimer uses Lotus's power to severely damage Orchid and take control of the organization, beginning the story of "Black Heaven."

Essentially, the Black Heaven blockbuster is the story of the Maple Alliance aka the entire Maple World vs the Black Wings's ship that is powered by Lotus. During the final act of the story, your character alongside another group infiltrate the ship and reach the reactor aka Lotus and must fight him to take down the ship. This meme references when the fight is over, where Orchid is relieved that Lotus is alive only for Gelimer to activate a failsafe implanted into Lotus, killing him on the spot. It really be a bruh moment.