Deflectors on - Geb support build. (Patch 3.5)

For you starting item you can take watchers depending on you playing aggressive or more passive because if you play more aggressive and poke at the enemy more, you will want to grab watchers so you don't have to focus on farming. IF you stick with mov you will need to use shock wave on each minion wave, to keep your xp/gold up.

For your fourth item, pick pestilence if you're against a healing support. If not go for a physical protection item, like sov or spectral.

For your fifth item you want to pickup a magical protection item, unless you got pestilence for 4th. I would take heartward or genji's.

Before the game you will want your adc to clear the back harpies while you and the mid take the red buff. After the red buff camp and back harpies are cleared, take out the two boars. After you do that you while head to lane. If you want to ward before clearing camp ward in front of the other team's boars and in between the closest mid camp and the other team's red buff.

During this time you and your adc will be farming minion waves. Avoid heavy conflict with the other team until you are confident you can get the kill/kills. If you mess up and give the other team first blood, you are at a disadvantage. Another thing you should do is clear the boars whenever they're up, it gives you that extra xp. If the other team's support rotates to mid, you shall rotate as well. You cannot leave your mid in a 2v1 situation. Another thing to keep in mind is if you die for your adc they can keep farming and get ahead of the other team. So if you have to, die for your adc. When your adc gets a stacking item you must allow them to kill all the minions, its ok if you end up underlevel. You can hit the minion wave with shock wave to soften them up, that's one good thing about Geb, he can assist in clearing the wave. Since you are Geb you have the shield, that shield can be crucial to the life of a team mate, so reserve your shield for hard pokes or enemy ganks. Your ultimate ability takes away a guaranteed percent of the enemies health, you must use the to your advantage and have the start a fight before you use shock wave and before your adc starts attacking, this will maximize the damage form your ult.

After the laning phase is complete you want to focus more on helping your mid. Mid is where the majority of the late game takes place. Taking jungle bosses is very helpful, don't waste anyone's life to get the fire giant if you don't have to. The fire giant is extremely helpful to you final push. Do not go for the FG if the entire enemy team is alive, it is very likely someone will notice, the last thing you want is the other team flawlessly stealing the FG from you. During 5v5 team fights Geb should be the one to initiate with his ultimate, like I mentioned before it takes away 15% of their current hp, to maximize use that. If you have blink it helps you initiate better because you will not have to use roll out to get into ult range of the enemy team.