Elliot wondered how Barabara was stronger than Dante. But Apparently, even when Barbara was still Barbos, the raw physical strength that they have was overwhelming, so overwhelming that she was eyed on from the deepest level of the Abyss, the Den.
The Forsaken wanted to approach Barbos before the curse happened. It would've been the first ever Behemoth sighting for the Demons. Not one Behemoth has entered Hell publicly before, but Barbos could have been the reason for the first time that it would happen.
The disappointment on Malice was beyond everything after the curse happened. Although Barbara maintained the power that she had when she was still a man, the Forsaken dropped the communications between the two regions.
"But that's what everyone thought happened," Dante suddenly added. "Right before the messenger could leave the Den, the Shift happened. Magic in the Den became unstable and disoriented that the Forsaken's power was unfortunately sealed away."