The "Boss Battle Fusion Collab", initially titled "??? Fusion Collab" before being renamed, is a high quality collaborative medley arrangement of various boss battle themes. It was initially premiered in the stream "Join us for the reveal of a mystery Fusion Collab!".


This collab has a unique structure from SiIvaGunner's previous fusion collabs; instead of being centered around a single song, each segment aside from the "Megalovania" opening is an arrangement of a boss battle theme (or the song associated with the boss in the case of Wood Man, or an equivalent thereof in the case of LazyTown and Yellow Submarine) from the game(/show/movie) of the previous segment's style.

Time Song Source


Boss Represented
0:00 Megalovania Undertale Undertale Sans
0:15 Megalovania Undertale Thunder Force IV Sans
0:31 Evil Destroyer Thunder Force IV Hyper Princess Pitch Gargoyle Diver
0:47 Boss Theme Hyper Princess Pitch We Are Number One Mecha Santa
1:01 We Are Number One LazyTown EarthBound Robbie Rotten
1:15 Pokey Means Business! EarthBound Puyo Puyo Fever Pokey Minch
1:36 The Untrained Demon King Ultimate Legend Puyo Puyo Fever Kirby: Squeak Squad Popoi
1:58 King Dedede's Theme Kirby: Squeak Squad Plants vs. Zombies King Dedede
2:18 Brainiac Maniac Plants vs. Zombies Yellow Submarine Dr. Zomboss
2:40 Hey Bulldog Yellow Submarine Crypt of the NecroDancer The Bulldog
3:14 Last Dance Crypt of the NecroDancer mm2wood The Necrodancer
3:27 Wood Man Stage Mega Man 2 Sonic the Hedgehog 3 & Knuckles Wood Man
3:49 Final Boss Sonic the Hedgehog 3 & Knuckles Splatoon 2: Octo Expansion Dr. Robotnik
4:02 Fly Octo Fly ~ Ebb & Flow Splatoon 2: Octo Expansion Paper Mario: The Thousand-Year Door Commander Tartar/NILS Statue
4:29 Hooktail Battle Paper Mario: The Thousand-Year Door Deltarune Hooktail
4:56 Chaos King Deltarune Super Smash Bros. King
5:25 Final Destination Super Smash Bros. Cuphead "The Mastermind's Hand"
5:53 One Hell of a Time Cuphead Undertale The Devil

At 6:08, the "One Hell of a Time" arrangement is abruptly cut off by the transition used for King for Another Day Tournament reveals. We then see the various visuals for the fusion collab's segments drift by, set to a calm, jazzy medley of the various themes based on "It's Raining Somewhere Else" from Undertale, ending with a "Boss Battle Fusion Collab" title in the Undertale logo's typeface.

After the screen fades to black, we suddenly get a "reveal" for Sans as a contestant in the King for Another Day Tournament. However, the logo's text turns into:

lol nahhh cmon dude
sans literally already said
he didnt want to be in the

This text references the reveal trailer "Knock Knock Knock!".

Instead of "SUMMER 2019", the text changes to "GET DUNKED ON", accompanied by Sans' soundbite.

Description Edit

Audio: Ahmaykmewsik, Anonite, Aquacycle, Chango, ChickenSuitGuy, Ethan64Music, Grambam36, Half Pixel, Harley201, LarryInc64, Mitchell, Moder112, Sarvéproductions, Scribblenaut19, Spingus, WaluigiTime64, Zoom Guy

Visuals: 600billionlazer, 813N, adumb, Ahmaykmewsik, Alexander A. McDonald
Anonite, Aquacycle, ChickenSuitGuy, Coach, Count Cannoli, Eevee, Harley201, Jorge - Sun Spirit, LarryInc64, Mitchell, Moder112, Sarvéproductions, Spingus, Tocinin, vince94

Video: Ahmaykmewsik
Thumbnail Art: Keeby, Sparkbag

Please read the channel description.

Trivia Edit

SiIvaGunner's Original Fusion Collabs
MOON MANSION RELAYPatched Plains Fusion CollabKirby Winter MedleyGO MY WAY FUSION!!Wood Man Fusion CollabKass' Theme Fusion CollabSoap Disco Fusion CollabSnowman Fusion CollabGod of ink fusion collabYule Log Medley CollabSuper Mario Land 2 Fusion CollabLifelight Fusion CollabBalcony Fusion CollabBoss Battle Fusion Collab7 Grand Dad Fusion Collab
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