When she meant that power she probably refering to the outside g** power residing in bam and for those of you who are confused read that sentence well and you will notice that full stop. Her last sentence meant that both v and bam will regret having a red witch to guide them( a red witch lore). Probably v also had a red witch to guide him during his climb and hwaryne is saying bam might also regret having her guide him.
But I dont get the memory she is talking about maybe gustang book
