Resistance? A slightly-harder-to-kill creature? That's effectively + 1 HP while getting around some HP-based effects. Gravity Shield is the first one that I can think of, especially for the upped, but I'm sure there's more.
That you need to have a Gravity mark to play it is an unusual and nice touch and probably useful for balancing purposes, though I can't say much for the whole Zodiac-based obtaining requirements.
Combo with Acceleration much?