If the Ancients weren’t stored in Sestren, then there would be no reason to give Abadd access to Sestren. By creating this fail safe, it would ensure that if Abadd fell into the wrong hands at least he couldn’t be used to break into Sestren. By minimizing the number of drones created to enter Sestren, it would make it harder for any intruder to enter.
Sestren is a data network.Physicall things can’t be stored there.
And yes you are going to say : how did Orta entered then…
I dunnno.
Well actually you can see the Ancients flying around in PD Orta 
Open Pandora’s Box and wait a couple of seconds. You’ll notice that it starts “snowing”. Compare those spheres to the one of the Divine Visitor. Notice any similarities?
You’re right about the Ancients limiting the number of drone that could enter Sestren Solo, but I really think Abadd’s mission was important enough to give him access.
Gehn, Sestren is capable of carrying physical things. They are converted into data before they enter. They are then turned back into physical beings when they exit the system. The question is: can you create something by “programming” it in Sestren and then turn it into a physical being?
It would make sense.
Better yet ( and thanx for the idea here Donut 
) : can you insert a dead beeing inside Sestren and then reprogram it to become alive when he comes out?
Could that be that what Abadd was doing in fron of that “pod”?
Indeed. That would make a good theory actually.
Perhaps Abadd could enter Sestren, but not access the section where Orta was created? Originally I thought Orta was created in the ruins from Episode 6, but it’s hard to come to any certain conclusion.
I’d imagine it would be possible to clone an entity that way. But actually reviving a dead being… well, I don’t know if even the Ancients would have had powers that advanced.
Well you haven’t seen the scene in PDS where Edge falls after beeing shot then…
Orta wasn’t created in those Episode 6 ruins.Well it could be her but it could also be the drago who “cried” when Abadd said that.
You know, you could make your own game by downloading tools like rm2k.