@Daniel
Read Hwaryne's sentences well. Translations goes off anytime. Baam's literally the reincarnation of V according to how she said.
Firstly Baam's memories were never sealed/forgotten in this current life. But V and the FH all sealed their memories in that book which Baam has copied the datas of it. He didn't actually have read it all but he's slowly getting the hang of it. That's why she said, he managed to get some of his memories back where soon 'that power' will awaken. Recall the past chapter where V gets a power up which definitely is 'that power'; hence that scene was shown in the first place probably. So Bam is basically V himself.