I find that the combination of the phantom star with black obsidian truly does something wonderful!
When I first purchased the Phantom Star I did feel it work for me the first times but could not really get into a flow with it. It was quite intense & somehow I felt my inner saboteur show up and resist it. So I did not use it for a while as it left me a bit ungrounded. Recently I have joined a womb healing container which is taking place for 9 weeks, and I felt guided to start working with the phantom star & black obsidian together. 3 loops of each. I felt it working with me so differently and it finally integrated in a way that felt “right” and “whole”.
& the black obsidian really helps me ground it and integrate it in deeper levels, clearing a bit further 
I get that we are all in different places needing different tools at different times:) for me it seems to be working well while I am already intentionally integrating and transforming a part of myself. But this is just from my observations so far.