On the subject of Siberian’s invulnerability, remember that she’s gone up against the Triumvirate multiple times. I think you can reasonably assume that she’s invulnerable to most things Legend or Eidolon can dish out, which goes way beyond just being invulnerable to forces.
Fuck, that’s true. Eidolon in particular should be able to find something to work around a selective invulnerability.
I did think about this factoid, yes, but I failed to consider it beyond Legend’s lasers (which were relevant to whether light could hurt her).