I mean, this is the case with Ramius, right? He exists, he was brought back somehow, but he doesn’t have his soul. So did the servants of the Tower who brought him back just save the lower soul while the upper soul continued on? Did the upper soul enter a hiatus of sorts because it couldn’t properly cleanse the lower soul? Will Ramius Krill have to kill a ten year old child to get his soul back?
So Adam’s reply suggests that something similar to resurrection can occur, but it has a time limit, I think is the best way to interpret it. Because you have to seize the lower soul, before it is purged, or otherwise removed/rendered obsolete. So, the Tower might sit there and go “I can use this person”, seize the lower soul, and resurrect it, and I’d assume leave the upper soul to continue in the reincarnation process. And I assume that because stagnating the cycle is what the Mara do and as a construct of the Arcana, the Tower would have to help perpetuate the cycle. Especially since the Tower represents rebirth through tragedy. To stop that rebirth of the upper soul would be against its very purpose.
Of course, since the Arcana are a human construct, I guess it could get corrupted. That’d be interesting.