Fan Works / No Body Left Behind

As a Death Trope, this naturally involves spoilers.

Beyond the Outer Gates Lies... A high school library?: Downplayed with Beholders; while they don't puff out of existence the moment they die, their bodies will disintegrate completely in a matter of hours unless properly preserved. Naturally, their body parts are highly valued as magical ingredients.
A Champion in Earth-Bet: Jack Slash gets atomized into dust by the Avatar.
A Change of Pace: Victor's body turns to ashes when he falls into the Void after the Bone Carver slits his throat.
In Kaleidoscope, there's no body left behind whenever an Agent is killed; only their Gem. According to their traditions, it's considered proper to take a Gem back to the Source as a Due to the Dead.
In Origins, a Mass Effect/Star Wars/Borderlands/Halo Massive Multiplayer Crossover, this is enforced In-Universe when dealing with the Flood since anything left behind can be reanimated and turned against their now-former allies. Catalina Rodriguez is one of many who receives this treatment (via disruptor blast), and the fact that there's nothing left to bury is brought up.
A Quiet Life: Thanks to the devastating combination of Bites The Dust and Aya's cleaning power, Coil winds up so completely obliterated that not even Emma's Thinker Power is able to locate them afterwards.
Raisin' Some Hell: Nick Necro is incinerated by Lilith, leaving behind nothing but ash.

Repairs, Retrofits and Upgrades: Omashu and the capital of the Fire Nation are decimated with spirit bombs that outright vaporize anyone caught in the blast, making it incredibly difficult to discern just how many casualties there were.

Danganronpa: Academy of Discontent: The culprit of Chapter Three leaves no body behind after their execution, due to being Eaten Alive by sharks.

What if Noelle Lost Herself? uses a Downplayed version for dramatic effect. Following the idea that monsters dissolve into dust after dying as they did in Undertale, the Awful Truth behind the mysterious disappearance of Berdly goes undiscovered for a significant amount of time, as nobody draws any connection between their disappearing and the computer lab at the Librarby being significantly dustier than it was before. When Undyne finally puts the pieces together and realizes the gruesome truth, she punches the wall while berating herself for not figuring it out sooner.

A Dragon in Shining Armour: The series' usages of this gets Deconstructed in Holy War. Since digimon naturally break into data when they die, it's never immediately clear whether any digimon who disappears is simply missing or actually dead... unless, of course, there was a direct witness to their death. As a result, it's typically assumed after a certain period of time that any digimon who's MIA is actually dead.

Parodied (along with many other tropes) in the Japanese Doctor Who video, where all it takes for the "Cyber Men" to vaporize is a meager hit. Nice effects for '70s amateur spoof, though.

Atomic Number 79: When Beerus destroys Vegeta, his body unravels into a gold cloud. It's as if he was never there to begin with.

The New Adventures of Invader Zim: Norlock is outright vaporized when Project Dominion explodes while they're still attached to it.

In Crimson and Emerald, it's believed that Touya accidentally cremated himself, due to Endeavor forcing him to push beyond his limits. Dabi's existence hints that this isn't entirely true.
Level Up: All For One accidentally inflicts this fate upon themselves by absorbing One For All, as they're destroyed from the inside out, disappearing in a burst of stardust.

The Flight of the Alicorn: In the end, when Windlass dies after nearly destroyed herself with magic misuse, her body simply dissolves into thousands of sparks of magic.
Harmony Theory: Happens to Charisma when she's mortally wounded during her battle with Rainbow Dash and the Element she was using destroys her body.
The Negotiations-verse:
- When Celestia is executed via firing squad for her crimes, they use magic-powered rifles that reduce her body to ash.
- When Discord passes away, their body disappears in a flash of light.
Pony POV Series:
- The Changeling's bodies crumble to dust upon death. This seems to be their body consuming itself to try and stay alive or a side effect of their stealth based magic.
- The Rumors Spawn disappear into shadow upon death.
- The avatars of the Outer Concepts all vanish in some way upon death. Abandon dissolves into black smoke, the Beldam crumbled to dust, and Shub-Neighurath explodes. Given the Rumors Spawn are her children, this likely explains why they do this trope.
Principal Celestia Hunts the Undead: Vampires and ghasts turn to dust when they die.

In Son of the Sannin, Maito Gai uses the Eight Gates against Madara Uchiha to try and hold him off while his students and the rest of the allied forces retreat. After delivering his strongest attack, his body disintegrates into ash.

Esurientes in Cibus Esculentus Madoka Magica disappear in a flash of light when slain, and even take any blood they've lost with them.

Light Lost: Karolina didn't have a body to bury, so the Runaways bury her trinkets and belongings instead.

Arc Royale: Ash's body dissolves into motes of light after he's killed by Null.
AZRE: Slain Grimm vanish into dust, leaving nothing else behind. The Stiched, which are people whom Merlot subjected to grimmification, take this further by melting into puddles of tar. This proves to be the fate of the Alpha Stitched, Yishaq.

The Smurfette Village: In "How Things Smurf", the bodies of the dead Smurfs in the Smurf Village all disappear when the magic shield that protects the surviving Smurfs and Smurfettes from "The Blue Plague" vanishes.
The Smurfs That Canon Forgot: In Smurf Village Upturned, Papa Smurf Disappears into Light upon dying. For an extra layer of tragedy, Brainy initially mistakes this for having a Go into the Light moment; his glasses were smashed and he can't actually see what's happening, just the resulting glow.

The Other Side: When Poppy destroys the Strings, their body is so horrifically burned that they immediately disintegrate.

I Woke Up As a Dungeon, Now What?: When killed, dungeon minions disintegrate into mana, leaving behind only whatever drops were created by the loot system, unless a Harvester uses their mana to make the corpse fully real. On the flip side, corpses left in a dungeon rapidly disintegrate, consumed by the dungeon for mana and impurities.

No Body Left Behind / Fan Works