Just a few confusions about items: Your "Mid Game Core" build is kinda focused on building resistances against AP. You could create two folders showing what to build against AD/AP because I feel like an item such as Sunfire Aegis is rather an early game purchase against AD even though it got hit in the past and it isn't the strongest of options anymore. How do you even come up with your full build and when is the time to build Ravenous Hydra? You should try to clarify this at least in the notes.
Just out of curiosity (I'm not playing Sion at all): Wouldn't it be better to build damage items rather buffing your abilities? I think Hydra is probably not used that often when fighting because you mostly rely on abilities.