this is basically a hexaminx with 4 extra verticies, and its quite an interesting puzzle except for the fact that turning this puzzle is near impossible, its extremely stiff to the point of being unusable.

The cube was very interesting - not exactly like any other cube in his collection (90+), so it took him a while to figure out. The tricky part, like some others have mentioned is figuring out which turns are “legal” and which ones could be a forced turn but not intended by the manufacturer. Btw, the name means “Two Birds Flying"

most people who are getting this cube or the "DaYan Bi YiNiao" in their hands, are complaining about the bad turning. This could possibly turn like a Hexaminx if the cuts were matching, but if they are over 2 or 3 mm apart from each other, people should think about if the turn is even "legal" or rather intended by the puzzle designer. You could say its somewhat a bandaged Hexaminx with 4 extra verticies.
I got myself this one here. The solve is extremely time consuming because you have to do so many setup moves (which demotivated me in the beginning). I needed a few weeks to solve it back to its cubic shape and all faces to approx. 99%.
I am now stuck with a parity of the little triangular pieces next to the face center and i am looking forward to solving this someday.

if you keep watching to do only legal moves (which is especially hard when shapeshifted) the turning quality is really smooth and clean after breaking it in.

Btw.: there are many different jumbling moves possible and its tricky and fun to see how to even separate some pieces.
In my opinion people are raping the puzzle to be a Hexaminx ;)

Solidly confusing... It's easy to get lost in the solve, at least for me. I haven't tried to jumble this cube thus far. OOTB, this puzzle is beautiful, I've placed a pattern on this cube which makes it look interesting. This cube's sticker placement is above average with no peeling or overlapping. Again, I haven't jumbled this puzzle yet which is where I've run across peeling stickers because of the rubbing. (Ex:DaYan Gem I) So far, this cube has been a delight to get familiar with. I have found that there is a gentle puzzle, meaning it's in no way a speed cube. This puzzle's artful design makes for a nice addition for a, what I call, a mature and complex cube collection. The function of the Pieces is harmonious in a strangely pleasing way. I haven't run in to popping or binding. I have added some lube to keep the proper alignments. I don't necessarily think that this is required. I just personally like to keep the more complex puzzles nice and loose. Overall, fun to pattern and gorgeous to look at.