Okay, so, I'ma let Forrest answer about Sleeping Goddess because she and Anthony were responsible for its modern form. Actually, they were also largely responsible for bringing Eternal Guardian into line, but let's talk about that. So:
> Eternal Guardian
Pic. Fucking. Related.
So once upon a time, Luke floated not one, not two, but /three/ "undead" disciplines at us on our forums, back before they changed over to their modern incarnation. One was for "feeding" undead (vampires, shadows), one was for "avenging" undead (revenants, graveknights), and one was for "warding" undead (mummies, liches). The bossman asked me to take a look at them, and I gave an honest critique, to which Luke replied by whining, complaining that they were all valid discipline ideas, and generally ignoring me.
He was added to my team about four months later. If you think I'm still angry about that, congratulations, you are fucking correct.
Luke was given the chance to cut his teeth on a psionic initiator class. He pitched us a concept of a psionic swordsman who used his power points to make 'meta-maneuvers', augmenting his disciplines and altering them on fundamental levels. It would include the PoW rework of Sleeping Goddess, graciously donated to us by its original author, and he also wanted Eternal Guardian in, retooled in its fluff to not be an undead discipline.
We got Zealot instead. If you think I'm still angry about that, congratulations again. You are fucking correct.
Guardian was ultimately kept for three reasons. The first is we already showed it and it got popular, which is part of the reason we're careful about what we show these days; there's been too many cases on us having to go back on something that turns out to be stupid, unworkable, or both, and then eating the hit for it. However, that's honestly the /smallest/ reason.