You may be a puzzle, but I like the way the parts fit.
-- Frank Sinatra

I need the save feature ...

The refinement is at my repo. The handle of history is enhenced, and there is one more button for dumping the history to a text region, so that the player can copy-and-paste the history to yet another text region to redo the whole sequence. Although this is not a direct save feature, but at least if I want to, I can dump the history (including scramble and the player's rotations and twists) during the playthrough and manually save it for later to load.

Still don't know how make a better looking frontend... never understand the CSS stuff. The ugly panel is functional enough though.

fight scramble 8 again!

From O3,

and from O1,

Form O1, it looks like the O2-O3 white and the O6-O7 white is part of the O1 tetrahedron, so make them together,

Yes they are. We can see it is at least the tetrahedron at first because they form consistent colors: green at X-, red at Y+ and pink at Z+. We do not know if it is the right timing to join them though. Anyway let's see how far we can go from here.

During the shots, I just spin the whole puzzle around and try to figure out what is what. The experience from 2x2x2x2 does help, but only a little bit. The edge pieces are still weird to me. I believe eventually I will get used to it, but unlikely before this series end.

This view from O7 seems interesting. The blue stickers at the center is near complete, but the adjacent triangles around the O7 tetrahedron is perfectly shifted. The coffee sitckers belong to Z- but at Y+; the oranges belong to X+ but at Z-; the yellows, while it is hard to say that they belong to Y+, but the whites are mostly at the Y- now, so it is kind of OK to make the move.

After the move, the view from O3 is

Interesting. I want to finish the blue at W- directly, but the rest 3 edges and 1 center (at Y-O2, cannot be seen form the snapshot) are all over the place. Not yet for blue I guess.

Maybe it is OK to go yellow? The O4 tetrahedron at Y+ is complete if O4-O7 yellow is ready, but the missing one, coffee-orange-yellow-null is at Z+O3-O4. A O4 twists looks good for this case. After the twist from O0,

The yellow looks good, because it is a proper tetrahedron. No obvious clue for the next move, I would like to deal withthe blue at Y- now. I don't think it is possible if we keep locking the blue at W-, so I want to do two X' rotations, like this from O1,

Originally I plan to deal with the blue but I now change my mind. The emerging yellow (which was at W+) has an interesting pattern. The greens look like a broken proper tetrahedron. The O0-O1 one is null-coffee-orange-green, the O2-O3 one is null-orange-white-green that can go to O1-O2, and the O5-O6 one is null-coffee-white-green that can go to O1-O6. The orientation are also convenient, because both of them can go to the desired spot in one simple twist. Even better, the two twists, a counterclockwise O2 and a counterclockwise O6, are independent to each other! Check what will happen after these two twists, from O1,

The yellow looks good but not that good. From X+O1-O2, we can tell that the orange-null-green-yellow is not in the right position. It should be a yellow-red face. I'm actually not sure what to do with it, but I think the missing yellow can be a hint. Z-O6 is a proper tetrahedron if X-O1-O2 can go to Z-O6-O7. This can be done in a single twist of O0,

Wait, from O6,

the yellows are not a proper tetrahedron... So we should revert the O0 twist (thanksfully a previous me has implemented that), and review the yellow in W-. There must be some inproper faces. I choose to finish the yellow-pink face now, so O4 twists, from O1 view,

From O3 view,

This is an angle to see that O0-O3, O5-O6, and O6-O7 are mis-positioned. The O5-O6 one seems to belong to O6-O7 with simeple O6 twist, from O1 view,

The W-O0-O3 mis-positioned piece is not easy to get rid of. A sequence to first remove it and then replace it should be used. I believe O0, O1, O0' should work. From O1,

The O1-O2 yellow has a green, so it should go to O5-O6. If we directly move there, we will inevitably affect the seemingly settled O6-O7 or O4-O5. I want to do two O6 twists, moving O6-O7 to O5-O6, and then move O1-O2 to O1-O6 joining it, and then one more O6 twist should settle O6-O7 again and O5-O6 at the same time. Let's check it, from O1,

Cool! I feel like a hyperskewb master already but still so far from that. In reality we already failed the depth 8 challenge. We spent so many steps already and yet it is nowhere near a solved state. I think that's OK because I can feel I am more used to this puzzle now. My goal right now is to see if I can resume the yellow cell properly. Interestingly, the green tetrahedron there is a proper one, but I see no use of it.

The rest yellow tetrahedron is not formed yet. How to form them and twist them back with other yellows while maintaining the yellows intact? This is the challenge.

towards the reduced goal

After about half an hour calculating the possibility to merge the tetrahedron then twist it back to other yellows seems really low. Maybe I should try another approach: send the single yellow back first, then move away the tetrahedron, then get the reduced tetrahedron (2 edges and 1 center) back, and finally get the tetrahedron back?

So the challenge now is, get X-O1-O2 to W-O0-O3. I believe a Y' rotation and a O0' twist can do the trick. From O1,

Yes, it does.

Conclusion

It's already too much for today. I progress is not good, at least not as expected. This is tough, way tougher than I thought. How do I even finish the 12 edges of a cell? I have to reduce the goal again. With intuition and some algorithms maybe, I should be able to finish a cell.

The history so far is

X,X,6,6,Z,Z,Z,7,7,0,0,0,2,6,6,2,2,6,7,4,x,x,2,2,6,6,5,5,6,0,1,0,0,6,6,1,6,Z,Y,Y,x,x,z,3,3,3,3,3,3,3,3,3,3,3,3,1,1,1,1,1,1,y,0,0,Y

小結

無法洞察原題的轉亂步驟以回復，就順勢來解，但進度不如預期...