Galio Update? I think I might have an idea...
I just bought Galio and his kit feels outdated but at the same time i'm having fun at ulting an entire team and let my ADC do the rest. I think that a slight change to his passive would make him more viable. He's really gated by mana because of ability costs and the fact the he rushes magic resist items first instead of mana regen. I guess you could buy Athene's early but you gain a huge advantage with Abyssal Scepter because it makes you tanky against AP mid laners and with his passive you gain quite a bit of AP too.
One thing that would make him better in my opinion would be to reverse his passive. What I mean is, instead of getting AP from MR he would get MR from AP at a smaller ratio. With this small change he could build things like Morellonomicon and have his MR gain but at the same time the ability to use his spells to harass with the mana regen and the cooldown. His autoattack would also need a small change. Either make it ranged (he's a mage after all) or increase his melee range and make him hit things with his wings. I only played 4 games so I'm not sure what the experienced players will think but I think with his utility and his kit in general he's only a few tweaks away to be viable instead of invisible. What do you think?