Well, it gives Darkness a bit more creature control, for one thing. As for Darkness and Earth having more synergy than Time and Aether, you may have forgotten about I've GotP Time, Fractal Scarabs ...
As for having the same stats as Anubis, yes, that was just a starting point. It still has to be refined and I'm open to suggestions.
The HP of Anubis is somewhat irrelevant, anyway, as it can quint itself the second turn it is out. Perhaps the HP of Basilisk should be 1, and it gains a passive ability which makes it immune to the delay brought on by Petrify/Basilisk Blood? I.e., it can give itself 20 extra HP second turn. Of course, that would somewhat undershadow (no pun intended) the ability of Gargoyle, so I'm not sure. Maybe Petrify/Basilisk Blood should just have no effect whatsoever.