As said above, you cannot max your ability at 8 and there are some other stuff. Other than that you started your guide nice with mastery and rune pictures but after that its just writings. Consider updating your guide with coding AND the rework.

You cannot max an ability at level 8!
I think you miss out the core aspect of buying Athene's Unholy Grail because you pick this item mostly when playing against AP and Morellonomicon if playing against AD. Claiming that Athene's is an option when being forced to spam hard or whatever would be a reasoning for buying Tear of the Goddess and not Athene's. Locket, Frozen Heart and Iceborn Gauntlet are way to extraordinary and as mentioned before you miss out building based on your matchup situation early on.
Your guide lacks of coding - this might help (don't forget to give credit)!