What would happen if you were to place 3 of these next to each other, would the effects stack, making this card unkillable via damage. Add gravity pull to that and you cannot die.
I'd assume it'd be like reflective shields: damage can only be redirected once.
Even with stacking, you would not be invulnerable. The highest priority shield would absorb its damage first, then die. Followed by the next. Then the central shield would be left vulnerable since it won't benefit from its own shielding.
The maximum amount a shield could absorb would be 25 points of damage, and only if you sunk 75 quanta into to casting it.
Getting 3 shields next to each other with that kind of absorption would take over 200 quanta and require either a quartet or rainbow (remember that they absorb all of your quanta of a single type when cast), or else would have to be done in several turns.
This is easily countered with quanta denial, or reverse time. Or you could just stun or freeze the two edge shields and kill the central one while its open. Or better, lobotomize the edges and watch the shields dissappear.
Lastly, you would still be vulnerable to momentum, rev. time, weapons, and spell damage.
Given the difficulty in set up, and vulnerability to CC, I think you're better off with a dissipation shield. Its more cost effective anyway.