Aww, thank you! There were many more interesting ones, but some way out of my price range (I am still trying to find some Aztekium specimens, but they're pretty rare in Japan and super expensive because of that)
It might be mislabeled of course, but that's what it was sold so me as, and the seller seemed pretty professional.
The spines on both tephrocacti are pretty thin and flexible - you can easily bend them with your fingers. I do love the variation with curly spines - haven't seen one irl until today, so got it on the spot :)