It is finally time for him to come back
The only question is, how would you build him? Since if you go too hard into AP, you get blown up before healing.
The conservative approach would probably be D&D + Riftmaker into Visage and Unending Despair. That way you have a lot of haste to have lots of E uptimes. Maybe a Shojin would fit in here as well or something else? Rabadon's?
Shiv would be the meme multi proc item for fights, but other than that, it kinda doesn't give you what you want. Sure, the AS is nice, but neither haste nor defense kinda stinks.
Wouldn't go Nashor's at all, too extreme in terms of offense. Makes you just blow up.
Another crazy idea would be going D&D + Rabadon's into Visage + Despair.
One question is tho, does his E AS scaling work with runes like Legend:Alacrity or AS shard? Cuz for Garen spin and Kai'sa E evolve it doesn't.