@riot, I feel like nashors tooth and lich bane could be improved
By improved I don't simply mean buffed.
For nashors it feels like rage blade has taken its place in what it offers most champs that previously built it more commonly. Not only that it seems curious that it it an attack speed on hit item that doesn't build out of recurve bow while all other items have proper continuity with their components. I think adding an on hour mana restore on top of its damage component would be a solid way to have AP champs manage their mana in a more interactive way, much more than archangels does now.
For lich bane it feels like the neutered AP counterpart of trinity force. Even on AP champs with pretty blatant synergy with it they feel better to just stick with stacking high AP items. I had an idea of making the spell blade just 100% base AD like its sheen component and instead of extra AP scaling on the spell blade add a second passive offering (+30% AP)baseAD. with the plan of detaching steraks synergy with trinity force which I assume will be through the removal of base AD scaling it should remove the concern of abuse interaction of a too strong item combo. And with improved base AD's on AP champs they will be encouraged to have more offensive intersection even between spell cool downs.
For both changes together it would give AP champs improved encouragement to play a little more like marksmen by having higher inclusion of auto attacks in their damage patterns.

.....
even playable...