Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
I've been playing Galio a lot more often since he has recently received a few buffs. His buffs were not an incredible adjustment, however one of the bigger changes he received was increased range on his Ult. This buff alone has increased the effectiveness of having Galio on a team. I play with a group of guys and usually run Galio tank when we want to win a game. With this build i can usually tank at least 3 of the enemy team members alone without dying. I can tank all 5 of the enemy team with my team with me, thats me using my ult to taunt them and then us rolling straight through them.
All in all, try this build before you comment or vote.
The runes I chose give a great advantage early in the game. The extra health helps out with early laning allowing you to stay in lane earlier and in combat with the opposing laning team. The dodge runes in conjunction with Dodge masteries are incredible, it makes all the difference in winning a fight with auto-attackers. The magic resist gives you an incredible advantage due to Galios passive. With this set up you go into your lane at lvl 1 with 58 Magic resist. If your laning against AP this is just l...o...l . They wont be able to hurt you at all.
The items i've chosen are not traditional of Galio and dont necessarily maximize the potential of his passive, however that's not the intent of this guide. This guide is designed to build galio as a tank, not and AP monger. Which regardless of how much AP galio has, he will never be a strong nuker end game, the effects of his abilities are far more useful then the dmg they do. So the item line up can be changed depending on the team your facing obviously. Thornmail i typically get mid to late game because it adds effectiveness to Galios Ult. Getting the Warmog early on definitely helps in early/mid game ganks. The chalice is essential for the laning phase as galio is very mana dependent. Merc treads are self explanatory.
One of the strategies we utilize to our benefit is AoE ults. There are so many AoE ults out there that go great in conjunction with Galios taunt. One of our best set ups consists of Galio, Nunu, and Twitch. You can pretty much have any 2 other team mates and be fine. We will go for a team fight, i use Flash to help set up the perfect ult for me, maximize the number of enemy's affected. Nunu comes in on top of me and uses his ult at the same time, all the while twitch is using his ult while they are taunted and slowed. This combo almost always works and allows us to push through turrets.
These masteries are self explanatory for a tank. I chose the dodge bonuses to maximize the effect of the Dodge runes.
Pros / Cons
Great Taunt ability
Low ability ratios