Hello again guys. This is my AGL support / Tank guide.

Before running AGL you must understand how to play support. You're a body gaurd, plain and simple. Your job in lane is to ensure you carry gets farm and make it harder for the enemy carry to get farm. If the lane gets ganked its your job to make sure the carry doesn't die, even if that means you have to. During team fights your job is to distrupt the enemy team and help secure kills. I hope this guide helps you get a feel for AGL and/or hopefully inspire you to grow from it.

Abilities

CONSTRUCT CHAMPION (Q)

Arcane Green Lantern constructs a knight that marches forward, dealing 50 Power Damage and knocking down the first enemy Champion it touches for 0.5 seconds. If Construct Champion is activated a second time, Arcane Green Lantern will blink to the knight's location, taking it's place and dispelling it.

Damage 50 90 130 170 + 60% Total Power Damage
Debuff Time: 0.5 0.6 0.7 0.8+ 0.03% Bonus Will
Cooldown 16 14 12 10

This ability is very useful not only for CC but for movement as well. Grab this first because of this. Use it in the laning phase to peel for your carry and setup trades and pushes. Early on it has a high CD so don't use it recklessly as you may need it in a defensive manner.

SHACKLES (W)

Enemy Champions near Arcane Green Lantern's lantern lose 10% Move Speed while they remain within range of the lantern. If they are still within range after 3 seconds, then they will be rooted (unable to move or use movement abilities) for 0.5 seconds.

Slow: 10% 20% 30% 40%
Root: 0.5    0.75    1     1.2     5+ 0.04% Bonus Will

This ability is your primary tool for team fights. I know knocking someone down is sexier but slowing everyone around you with the likelyness of rooting them is very effective for initiating and securing kills quickly. In lane use it to discourage pushes and setup ganks. Since its slow and its root scale very well this is maxed first.

EMERALD LANTERN (E)

Active: Arcane Green Lantern throws his lantern, dealing 50 Power Damage in an area. The lantern remains in the targeted spot for 12 seconds, granting vision of the area. If he touches the lantern, he will retrieve it, and Emerald Lantern's current cooldown will be reduced by 6 seconds.

Damage:50   100  150  200  + 40% Power Damage
Cost:      40      50    60   70

This ability allows you to place vision, poke and setup your chains from far away. While this skill has some utility its CD does not scale and you are not here to deal damage. This ability is maxed last but picked up if for nothing else pad clearing. 

DENY THE BLACK (R)

Arcane Green Lantern channels for 2 seconds and then teleports to the targeted ally. As soon as he begins channeling the ally receives a shield that blocks 250 damage and lasts for 5 seconds, and the fog of war is revealed in a large area around them. Enemies within this area receive the Emerald Light effect.

Shield:   250  375  500  625+ 25% Bonus Will
Cooldown:165  150  135  120

This can be used to save teammates but be cautious that you don't just give the enemy two kills instead of one. Look at the situation and see if you can prevent a death or turn the tide. If you can't, save the cool down. Its a great tool in a team fight. If after you have used your abilities and a carry is still in danger use it to shield them. This is also great for when you disrupt their carry and can easily jump back to your team. Its very useful which is why you should think twice before using it in an unsure situation. See a teammate running: how many are chasing? how many enemies are MIA? were they close? does the teammate have the damage to effectively turn the fight with your help? If its fishy then save it for when a team fight opens up. This ult will make the difference in a 4v5 if forced into one but if you die, the teammate dies or worse you both die, you have either a 3v5 or a 4v5 without your ult. Lesson: think before you use it outside of a team fight. 

EMERALD LIGHT (PASSIVE)

Arcane Green Lantern's lantern grants nearby allies 10 Attack Armor.Trigger: When Arcane Green Lantern damages an enemy with a Basic Attack, they receive the Emerald Light effect for 3 seconds. When an allied Champion uses a Basic Attack on a target with Emerald Light, that ally regains 30 Health over 4 seconds.

Heal:  30  45  60  75+ 7.5% Bonus Will
ATK Armor:10  15  20  25

This is going to be your lane sustain. Try hitting the targets that your carry is going to last hit. This allows you to heal your carry while they farm. But remember you don't get healed unless you hit for a second time. So if you need the heal hit a full health creep so not to take farm away and not push the lane more than you need to. This ability can be leveled early if you are going against two ranged characters and are getting poked harder than can be returned. Just be sure you follow up and hit the marked target. 

Items / Mods

With the current patch running double gambit investment mods is too strong to not use. The last mod depends on your preference. I am a big fan of accelerate Will Battery for abin sur's lattern. This will allow you to build your will pool with tier 2 very easily. The alternative would be Empowered Pandora's Box but only if you intend to use the item. And this would be the reason to use the item as the active is not useful with just one charge.

That being said I still think the abin sur's is a bigger benefit to have as it will allow you to build other items without having to worry about will early/mid game.  This will allow you to jump right into Atlanteans Royal Seal. The skill harass will make your slow stronger and your E serve as an additional slow. Sure your Q will be helped but only if it hits multiple people. 

From there start building defensive items based on your opponents. Steel's Breastplate is a good starting point for this as it allows you to use your will pool to take some of the hits. While doing this be sure to upgrade abin sur's with spare credits whenever buying. Entropy Aegis would be the next step the will will synergize well, the power armor will round out your defense and the skill block will be great at absorbing shots. 

After that use your judgement on which item suits your team better. 

Will add more soon.