A Wisp of firelight
Lin Qiao gave that guy she bit a flame power which he described as similiar to that of the 'Chief' that died recently. From the other sidestory we learnt that Lin Qiao was theonly family member that died recently. Obvious that Lin Qiao was that base 'Chief', so she was a level six or higher but the transmigration drained her strength and now she needs to build her power back up again.
The person who was the leader of Hades's base was her, it's quite obvious. She is the only one missing from the family, the sister that her family mentioned in the chapter, which had the black fire power with venomous air, died fighting with several humans with level 6 power, she told them to go to another base. I have no doubt that when she died she ended up in the current body.
A ridiculous theory and one that represents my wish to excuse her stupidity but what if she awakened two powers which represents life and death? The Netherfire is pretty deadly and with this green light and heal and purify power it looks like it can represent life. But because this two powers contradict each other, her life power sealed herself with a part of her memories and personality. She did said she was observant but we see how stupid and opposite to observant she was. And the 'Chief' didn't hear her family out about the danger of this traitor like we read in this one chapter. As a special ops soldier it kind of looks stupid not being able to see this hostility. I mean, if she where so stupid it's unlikely she should have survived as a soldier. And after she died, her life power was awakened and fled to her new body with the other part of her. Since she become a zombie, it looks like she never felt a superpower beside this space. So maybe because her other part died with this power. It's pretty ridiculous, but at least it would excuse her stupidity and explain why she only has memories one day prior to the Apocalypse.