Alright, first we're going to talk about the cave that Baam was in and about Rachel. I'll be sharing a link that has a lot of information, details and theories.
http://rptog.proboards.com/thread/78/baams-cave-hypothesis?page=1
Baam and Rachel
''Well, there are 2 options. Either he was sent there by zahard, hence his crest in the cave. Or by someone else, but who? The workshop? Also, who's Baams mother and father? Is he a son of Enryu? Or some irregular, hence he's hated and put in the cave as punishment? How else could he control shinsoo so well and be compatible with Enryu's thorn? And most interesting... Rachel was forbidden to see him. I argue that the hand pulling Rachel's hair could be one of two options. There is a third one: It was Baam, but I don't see any evidence other than the fact we have only seen Baam and Rachel (and a 2nd girl) in the cave. My first option is that someone pulled Rachel away from Baam, because she is not allowed to see him. The reason I don't think it's Baam pulling her is because she's looking straight foward. She's looking at Baam. Which leads me to the second option. Is she yelling at baam to run away? Maybe she is not being pulled away from Baam, but just being attack by someone trying to kill or punish Baam. The ingenious part is that SIU draw her looking to a side. She's not looking to us, nor can we see the back of her head. Meaning either baam was hidden (but I doubt it), or just that SIU doesn't want to reveal if it's baam pulling her, her looking at baam, or if baam is hiding somewhere (which I still doubt and don't don't it as an option)'' - Ouro.
As mentioned, someone pulled Rachel's hair and the real question is who can it be? We know that Baam and Rachel was alone in that cave and nothing more than that. We know that Rachel somehow came in to that cave later on but what was the real purpose for her to come in? Did she know about Baam? And now back to the question about who were pulling Rachel's hair again. Who can it be? Ouro mentions some options but the only one I can think of is the third one. Maybe it was Baam that pulled her hair? The reason to why I believe this is that Rachel is afraid of the night and the ''25th Baam'' is translated to the ''25th Night''.
The next thing that I want to talk about as mentioned by Ouro is that why the cave is near the entrance to the Tower? Why is someone like Baam trapped in a cave that is so close to the door to the tower? Was Baam feared by someone and got trapped inside that cave or does someone want Baam to climb the tower? Even Headon the administrator of the first floor wasn't suprised when Baam entered? He even said himself that he had been expecting him? And even SIU mentions in his blog posts that the first floor spoils the story of TOG.
Furthermore, we know about people that are called ''axis''. And up until now we only know about one and that is Phantaminum. No one knows where he came from or how he became an Axis user or where he is right now. It is stated on the TOG Wiki (
http://towerofgod.wikia.com/wiki/Axis) that an Axis needs to awaken it's power but how do you awaken a power of an axis? The only way I can think of is to climb the tower and get to the last floor and then when you awaken the power you destroy the tower and become free? SIU stated that when someone awakens as an axis he or she destroys everything around them so that's why I think that you need to destroy the tower. That is the only way to get out.
Enryu
SIU also stated that after killing the administrator on the floor of death Enryu dissappeard and Headon is searching for him. But why is Headon searching for Enryu? is it because Headon is the only administrator that can pop up on all the floors of the tower and need to keep the rules in check or is it because he wants something from Enryu? SIU mentioned before that Enryu can be seen as a op character. Almost like someone with a ''cheat'' which leads me to believe that Headon wants to know where that power maybe comes from? As far as we know Enryu is the only Irregular who have killed a administrator.
Also as I mentioned earlier, when Baam came in to the tower Headon was expecting him right? And right now in the story Baam has the thorn that has the power of the Irregular Enryu in it right? Maybe Headon stopped searching for Enryu and got his sight on Baam right now that he knows that Baam has the same power as Enryu? This will also lead to Headon getting information about that power by observing Baam.
----------------------------------------------------------------------------------------------------------------------------------------------
A quick thought, in one of the TOG synopsis I read before starting the series it mentioned that baam was a prisoner living below the tower. Taking that into consideration he must be someone to be frightened of. Someone greater than Urek, enryuu and all the other irregulars cause the change baam brings can probably threaten the very existence of the tower. But if baam is indeed a prisoner wouldn't there be people after him? I mean his original captors that is. I think there is another strong group waiting to be unveiled in the shadows similar to FUG but more like the keepers of the tower or something. Someone built the tower and someone maintains it. That someone also imprisoned baam assuming that the synopsis got it right. - BleachXVI
Honestly, I think that this is Baam's universe and he is an Axis. He will awaken his power and destroy his universe. And the reason to why I believe this is that SIU shows a lot of ''Universe'' pictures in the first chapters of TOG.