If you long rest often enough, you would learn all there is about your condition by mid Act 1. You are on a time limit, but the night you're supposed to transform into a mind flayer, something else happens.
You will not long rest that often unless you do side quests/the underdark, though. End of act 1 is more realistic. Had you continued playing, the githyanki lead would have lead to nothing and you'd be back to Halsin. There is about a 10% chance for battlemaster Lae'Zel to pass the deception check and not be slaughtered by the Githyanki patrol at level 2-3. if you do pass it and enter the Creche, you would learn everything about the artefact.
In truth, the early gameplay is mostly railroaded as well. Picking the wrong enemies will not let inexperienced players survive. You also did definitely skip over dialogue as the game very specifically introduces you are shielded by the artefact when you meet the three shrouded figures (who try to mind control you right then and there), yet you've forgotten/never learned this??
"We cross the bridge west and our characters fall to the ground and have some vision about three shrouded figures. An artifact, just like the one Shadowheart had appears in front of us. My character takes it. It's bound to me apparently. I proceed and we're brought to camp. I go talk to Shadowheart. She tells me that the githyianki want the artifact. Specifically, says this:
"That thing is shielding us somehow. I don't want to know what would happen if we lost it." ????????????????????????????????
Now my replies are even more puzzling.
"There must be more to the artifact. You were sent to take it, you must know why it's so important."
"The artifact is shielding us, but ultimately, you wish to give it away?"
She was sent to take it??? WHAT? I NEVER EVEN SPOKE TO HER. How does my character know all that??? And it's shielding us??? Since when?"
