Sara wrote:Shadow element most likely refers to the same thing as Michael; Unable to be destroyed outside of Planeshift, as you may have noticed.
Nope, turns out this is incorrect. Shadow element enemies are only vulnerable to bomb damage.
The first enemy that this can be tested out on is Pamelah in Stage 2--her four orbiting flames are shadow element and cannot be damaged even in planeshift mode. However, Jet's regular bomb and and Pearl's Silent Judgment counterbomb will destroy these flames, leading to a change in Pamelah's bullet pattern.
So that means you'd need to counterbomb somehow to destroy Machina 13th's bits, which seems like a great deal of work as Pearl - Sapphire and Jet have a much easier time with this.
Having to defeat Eclipse and Full Frontal every time in Practice mode is getting tiring, and it's much quicker to take down Machina 13th the regular way, so I think I'm giving up for now--just gonna shoot for the regular 1cc. I also suck too much to get the Alter Break on Lotus, so 14 breaks will have to do.
(
i did finally break the 1bil mark last night, woot! 
took 42 hits in the process and had a very depressing death at the end with a life item floating on screen)
Edit: Having said all that, I've discovered that the point to counterbomb as Pearl is right after the 4x flamethrower attack, right when you get hit by the black hole attack, destroying all four bits and sending Machina into missile mode--it's fairly simple to collect enough gems for the Alter Break after that. Next problem will be how to not completely fail against the TLB if I manage to make it that far!