OptiMAX builds has been designed in relation to mathematically correct builds. Unlike the mathematically correct builds, the OptiMAX builds are intended as maximizing the chosen champion's abilities, passive, and playstyle instead of maximizing a particular trait as in mathematically correct builds. The OptiMAX builds are designed to maximize skill damage as much as possible, emphasize the passive but above all, it is designed in relation to how the champion is played, and it is probably the most important aspect of this build.

AFTERSHOCK
Is a must have on Galio, if you think about it, when you stun the enemy with your W and your E, you proc Aftershock. It gives you not only resistances but also bonus damage. I really think that is the best main rune for Galio, hands down.

SHIELD BASH
This is a particular one. Because the passive of W you can't really control when this rune will proc, but, Fimbulwinter will help you to proc the rune constantly giving you survavivability and bonus damage.

CONDITIONING
Why Conditioning instead of other runes? Galio's passive Colossal Smash has bouns dmg based on magic resistance, and give overall a better survivability if confronted with Bone Plating.

OVERGROWTH
You have to maximize health because health gives you more damage on W and because it scales with Demonic Embrace. You have to stay in fight for proc Demonic Embrace and hopefully Sunfire Aegis, that combined with scorc, considering that Galio has high cooldown on his skills, is great for survivability.

TRASCENDENCE
You really need faster cooldown, and considering the bonus ability haste and the fact that when you get lvl 11 you will have 20% cooldown reduction on basic abilities when you got takedowns or assist, you can easily understand why this rune is so important on Galio. Without your abilities you're pretty much completely useless.

SCORCH
Think about this way, youre not late game champ so you need something that helps you in laning phase, and also synergizes whell with Demonic Embrace and Sunfire Aegis, so you have some damage also when youre not casting skills. Something like Gathering Storm is too far away for give you some advantage and you also focused on tankiness. I tried several solution on this but this one is the best choice for me.

ADAPTIVE FORCE
ADAPTIVE FORCE
HEALTH