Well, in Paradise Apocrypha, souls are an 11/12D emanation of sorts, so all hax related to the soul is rendered to that scale. That also means their power source, spiritual energy, is what allows them to reach High 1-C/Low 1-B levels of power, and said power source is the source of information itself. Also, she can destroy souls, souls...so her hax is definitely High 1-C scale. Gabriella kills God himself in such a way, through soul destruction, albiet in a way that scales to attack potency due to the weapon she used as a medium.
Lulla's powers and abilities themselves don't change with her keys, only the full scale of their potency, the AOE arguably remains the same. I mean, 4-B Medusa can mind hax people all across space in the past, present, and future, which is Low 2-C and 4-B Lullabelle overcame such feats. I need to make a blog explaining Jacob's ladder and the Great Chain of Being, but Lulla basically can affect and resist powers/abilities on a High 1-C, possibly Low 1-B scale, even in her restricted 4-B key which only restricts physical stats like AP and dura.