I'm not sure if it'll be the last task. Aiden is a driving force in Sophia's corruption, if sex is his last task he'll be one of the last to have sex with her, and I don't think that makes sense. Aiden's corruption is probably going to be the thing that makes Sophia more willing to cheat. I think the final tasks will be increasingly debauched scenarios. Sex, already oral, will begin sometime around tasks 15-19.
It's true that Aiden so far seems to be the driving force in the corruption and there will be incremental steps, even if we don't know now what and where will be the final goalposts.I initially thought we would have 3 tiers of tasks of roughly 4 tasks each tier. Tier one just being teasing, tier two being sexual actions without full sex (naked boob fondling, fingering handjob etc, and then tier three starting with oral sex and progressing upwards from there.
Before anyone asks, no that is NOT based on any information or even rumour, just my impression of how the tasks MIGHT escalate. And I said roughly four - of the first and/or second tiers were five tasks that would nt surprise me unduly.
Now what I had not factored into the above, is to what extent Aiden wants to fuck Sophia himself or if he simply gets off on having control over her, in which case he might be manipulating her into doing sexual acts with others.
(Also there was the previous discussions on how much longer Sophia would / could be manipulated by Aiden and at what point does she do the tasks because she enjoys it, but I don't want to argue that round in circles yet again.)
But I don't think it can have an effect the other stories that are in parallel and not even related to it.
At the point we are today, PD 12, nothing particularly "disrupting" has happened, the classroom and the art modelling are still things that Sophia can live with, even if they stepped up her corruption. So beside some occasional internal thoughts that reflect that, there seems to be no traces in other events.
The other story lines that are somehow connected to Aiden are Dylan's (if you initially sent him to the boarding school the story with Sophia is over) and Alyssa/Zac's (which, IIRC, in the future can "survive" even after dropping Aiden with comfortable solutions). All the others, the lesbian routes (Patricia, Ellie, Nathalie), Vicky/DeShawn, Sam, Bennett (even if we know is cut short) are unrelated to Aiden*.
Here comes the problem with parallel and optional branches. It's difficult to see how Aiden's tasks could influence the other routes, i.e. making easier for Sophia the choice of cheating, being itself an optional route. All the other routes must be "self-contained" and able to progress no matter the choices on Aiden's route. Sure there could be references as there are now, but they cannot be determinant for Sophia choice, otherwise an independent route should have two slightly different paths to complete the route. A nightmare, IMO.
I think it's still too early to have an idea of the general direction of the tasks, the spectrum is still too wide, from domination with Aiden involved, pure voyeurism and exposure (humiliation), complicity (Sophia liking more and more the tasks) to even a completely 180 turn with the hate fuck GingerSweetGirl mentioned.
* I only considered the "direct" dependencies in terms of choices and events, I haven't counted possible dependencies in terms of FW points, like to access to this route you need X points which you can only have e.g. if you chose Aiden's task. So it's possible there are other connections (and in case it would be nice to have this table of dependencies).