The Mysterious Fusion Reaper is the unknown villain that is set to be a major threat to the Locked Room Gang. Its alias was given because it acts mysterious, somewhat looks like a black reaper to those who see it, and confirmed to be a plant fusion. Not much is known about it, aside from its demonic voice. It is roleplayed by Fairy27 and is considered to be her main villain for the series In a Locked Room Season 2 (Challenge Episodes only), following her pattern of having this treatment for all Entities of an unknown dark plant group. In this case, the Mysterious Fusion Reaper's alias to that group is the Betrayal Entity.

It will return again in Season 5, the final season, of the same series, this time with the three other Entities cooperating with each other, and their leader.


Not much is known about its past, with the exception of falling Suburbia and other cities into ruin, which took years to be reformed. The Mysterious Fusion Reaper first appears in Outside the Rooms, and it is about to go back to the Locked Rooms for reasons. Later on in few rooms, it taunts Gruffle in getting the second key for the Life Fountain.

It occasionally appears after that moment, starting in Crystal Ski Caverns (only in a flashback), then in The Wacky Bob-omb Factory when it attacks Yoshi and holds the cage of Rosalina, then in Mass Attack, when it secretly brings back Necrodeus back before he got faded into oblivion. It reappears in Skyline Pigeon briefly as well.

It is set to appear more frequently in the future Season 2 episodes to make up its lack of constant appearances during Season 2A.


Not much is known about the Mysterious Fusion Reaper. It is described to focus only power and destruction, mainly to achieve its goals. It does not want to betray its three true friends, but anyone else allied with it, it will slowly try to betray them, having the title of being the Betrayal Entity, and someone that should not be trusted. It has a cold personality overall, getting strict at its minions, but can be careful.

These traits are only displayed at its enemies and some villains. When it is in its group, it is mostly protective and doesn't want the group to get disbanded in the future, so it wants to work hard for its friends.

Powers and Abilities


The Mysterious Fusion Reaper can teleport in any places and used to escape dangerous situations and to dodge attacks. It can send out dark pulses to darken the targets' thoughts and keep them distracted. It will also sometimes forget parts of their memories. It can get invisible to some enemies and cannot be attacked once done so. It can deflect any projectiles and boost them against its opponents.

It also wields a weapon called the Neon Scythe, which is used to cut almost anything and improve its powers.

Plant Food Effect

When fed by Plant Food, it will randomly select an enemy, which is usually it first thinks of. Then the death ghosts it will summon will haunt that random enemy, stunning him/her/it, for them to create a black orb to trap him/her/it. Surrounded by its sun power, it will almost completely drain the enemy's life energy, almost guaranteed to kill him/her/it. It will also heal the user by that amount.

Villainous Acts

  • Betrayed many alliances which made them fall apart.
  • Destroyed Suburbia and many other cities in an instant, claiming some of them its own territory. It took years for them to be rebuilt, and some of them never did.
  • Murdered many plants who were not loyal to it, as part of its mission.
  • Had kidnapped Yoshi once, which caused him to be inside the rooms.
  • Threatened the Locked Room Gang and tried to distract them several times. Mostly it was individually but started to do it as a whole. It wants to kill at least one of them, or better, all of them.



  • The Mysterious Fusion Reaper was called a male during its first few appearances.
    • It was also called with numerous alliases but those were because Fairy27 was not certain of its proper alias.
  • It is the second character who did not reveal its appearance and name when it first appeared. The first was Dark Dracul.
  • It is the one of the few main antagonists in Challenge Episodes to not have an alliance with Dimentio in any way. Rather, it tends to observe him sometimes, and like Galaximus, is not an actual enemy of him.
  • Despite its lack of appearances on Season 2A, much later, it, like Dimentio, Galaximus and others, will pose a great and very big possible threat to the Locked Room Gang. It may even become Fairy27's most wicked villain in the end so far.
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