It seems that quite a shitstorm happened while I was gone. I think my viewpoint on the problem is obvious, but since it came up, I will clear some things up since I have the opportunity to do so.
Bartimaeus wasn't ever a part of Akroma's lore when I introduced him. Originally, he was a manifestation of the void's chaotic state in a collective mind composed of countless levels of conciousness. No true form, voice, name, etc, only a conglomeration of chaotic forces.
And then Alucard, a powerful sorcerer who had access to powerful magic, bounded himself and enchanted a nearby suit of armor, and then opened a gate to the void and entered to escape his brother's betrayal.
In the void he met Bartimaeus, who taught him about the void (which is why he calls the sultanes the names Bartimaeus calls them instead of the ones actual summoners used) and showed him around. Seeing and being around Bartimaeus was a daily and common sight for the next 15,000 years, and then something secret happened and Alucard got bound to the Formless Form.
In fact, in development, Alucard was supposed to be a chaos mage after being bound to Bartimaeus, but I decided that the cast needed more void characters since it was all focused on Ashley, and gave him void power (which recently turned into spatial manipulation via void magic).
So yeah. Also, when writing lore, I try and make it as flexible as possible so that others can use it easily. Like in Alucard's lore, he is only a son among many others, since Dracula is immortal, thus having many families. There was barely any communication between Sanure and I when I let him put Seras in my lore, and it worked out due to the lore's flexibility. Same concept with the Other Place, which should hopefully be accessed once Alucard and Ashley get the Twilight Sigil.
Although as I played in this game, I learned that it is extremely difficult to get players motivated to do some 'extracurricular' activity. Nobody bothered to actually reseearch what Bartimaeus actually was. In fact, Alice knows more about Barti than everybody else except Alucard does simply because she had to look through a summoner's book in the Bewitcher's library to aid in her escape.
So yeah, lore should be flexible. I implemented a lot of void entities in my plots, like Selkihm or Gurk'sae. I didnt even consult Akroma about Gurk'sae.
So if you want to make lore better, do some IC research or something and actually be motivated about doing shit. Plots can't tie up all the loose ends.