Hardest somewhat playable song in a Rhythm game

[Bigbadbrat]

What would you guys say is the hardest mildly playable song in rhythm game (customs included). These include "Valkyrie Dimension" Challenge (DDR X2), "Paradoxx" D28 (Pump it Up), "Egoism 440" Challenge, "Soulless 6" (Exilelord's Guitar Hero custom), "Over the Period" Challenge, or something else? This only includes single player songs (except in the Pump It Up examples). Also TTFAF and TDWDTG weren't included because the examples below are even worse

"Valkyrie Dimension" Challenge. Considered the hardest DDR song for the longest time.
https://www.youtube.com/watch?v=Hromx6HeN_w

"Egoism 440" Challenge. 440 refers to the average tempo and there's 16th notes towards the end.
https://www.youtube.com/watch?v=l7Vx5FvX7-E

"Over the Period" Challenge. Those slowdowns are insane and make the Pluto series look reasonable.
https://www.youtube.com/watch?v=YKQX0kgiNtI

"Soulless 6" (Exilelord). It's a Guitar Hero 3 custom originally but even the bots can't FC parts of this.
https://www.youtube.com/watch?v=5gMspNaL2S0

"Paradoxx" (D28)
https://www.youtube.com/watch?v=rquLGNHuxvI

"Bemera" D28. One of the most infamous songs in Pump It Up history.
https://www.youtube.com/watch?v=SExxVYHfMGs

"Vertex 2" Expert. Possibly the hardest song in In The Groove.
https://www.youtube.com/watch?v=16b5dp748Eo

"Mendes" Black Another. It's crazy even by Beatmania IDDX standards. Total notes in two minutes, 2626 (on Black Another) or 1831 (on Another).
https://www.youtube.com/watch?v=Y57snv0G0TI

"Mei" Another. Possibly the craziest and most infamous Beatmania IDDX song on Another (the highest normal difficulty). Exactly 2000 notes in a little over 2 minutes.
https://www.youtube.com/watch?v=yW34iG4bsQw

"Operation Ground and Pound" by Dragonforce Expert (Rock band 3 chart). It's freakishly overcharted and it's DragonForce. Nuff said.
https://www.youtube.com/watch?v=jIS52CW3Gdg

Edit: Added "Soulless 2: Mechanical Machines" (GH3) by ExileLord. It's been 7 years and there still isn't a legitimate FC.
https://www.youtube.com/watch?v=_-fy2FsFDiM

"Dystopia" by Chaotrope Expert. Chaotrope (creator of some of the hardest RBN songs) said this is possibly his craziest song.
https://www.youtube.com/watch?v=WuQJ8_CRL70

"Cypher Gates" MX. Considered one of the hardest songs in DJMax Technika for good reason.
https://www.youtube.com/watch?v=NJ8hle83ZF0
"Xeus" MX. See "Cypher Gates".
https://www.youtube.com/watch?v=xxlU0vW0JbA&t=2s

FOF songs that deserve mention include; Francesco Fareri - "Suspension" (sean2490), "Dark Matter" by Rusty Cooley (Puppetz Hero 4), and "Soul of a Robot".

Maybe you guys got a choice that isn't there ...

Edit: Added reasons why explainations for these difficult songs (on most of them anyway) and an ITG example.

[ONAONEMEU]

Francesco Fareri - "Suspension" (vedicardi)
"Dark Matter" by Rusty Cooley (Puppetz Hero 4)

(edit: right,i know you mentioned fof customs but they are undercharted compared to the ones made for gh2/3)
change suspension chart to sean2490 and dark matter chart to trunks252


also,the gh3 video is a song at 150% speed,don't think that's reasonable to compare a sped up song

[Bigbadbrat]

Alright removing GH3 150% speed custom.
So what's the hardest song in a music game (with the above considered)? What would your choice be?

Edit: I really added a lot of examples ...

[Bigbadbrat]

Seriously, does anyone know what the hardest mildly playable song in a rhythm game is? If not one of the above examples, what could it be?