So Galio already has a niche as an Anti Magic Warden, but the waveclear necessary to allow him to even function mid lane is also making him overwhelming top lane. We can't just nerf his waveclear straight up because any nerf done to his waveclear top lane hurts twice as bad for his mid lane. Instead, what can be done is to weaken his waveclear's flat strength while still granting him the firepower necessary to keep pace in mid lane.
Idea 1: Winds of War now scales on Magic Resist
Simple case of Flat Stats down, Scaling Up. This ties Magic Resistance to his basic function as a champion, instead of a neat bonus like it's currently used on his Passive and W/R resistance. This change also grants more flexibility on the AP scaling on his Q (aka, you can safely nerf it without gimping its scaling entirely), allowing you to unhinge some of the raw power behind Triple Doran's Rings. This also means he still has an avenue for creating a damage based preasure on the enemy team while still being a tank, meaning it's also safer to nerf the %Health damage currently in place on his Q.
Idea 2: Winds of War gets buffed if Galio has been hit by Magic recently
Thematically, I find this version far more consistent with who Galio is in the lore and far more capable of generating interesting gameplay moments. This way, Galio doesn't just statstick his way through Magic Damage dealers, instead he actively has an element of play based on those Magic Damage dealers. I have two ideas currently set in mind: The first makes the buff time based, for example for the next 2 seconds after getting hit by Magic Damage, he deals more damage in return. The second idea is to tie it to his W shield, for example giving him a minor bonus whenever the Magic Shield he has pops.
Either of these ideas or even a combination of both can be justifications to lower the general power of Galio's waveclear, while still preserving it for the match ups he's made to fight against. Thoughts?