Ok this is my first guide and i made it because i couldnt find any else with anivia support so i made a build up myself that i have tried, and i think its good. Though i have only tested it on bronze games.
So yeah i wont spend too much time on this guide just get it out and get it published.

Anivia is mainly played as AP mid but anivia has a lot of CC that can be used to save ADC. But before i go into this i wanna explain one thing. People like to counterpick mid champions so if you pick anivia as support, then the enemy team will pick a champion to counter anivia on mid, and after that you just pick a counter to their mid. Very nice.

So in the laning face at lvl 1, do not use the q, only use q if the ADC is in danger and the enemy has to be stopped. At lvl 1 u just harash with autoattack. It works.
So at lvl 2 you use Q then E to harash. And rememeber to stun any enemies that is a thread to ADC.

At lvl 3 you get a wall that you can place either to prevent enemies to escape which allow ADC to inflict even more damage on the target or you can place the wall in such a way that the enemy can attack you. This is useful in preventing ganks. Also you can use the wall to scout in bushes, but be careful the cooldown on the wall is huge.
At lvl 6 you get the storm (R), which is nice. It does damage, but not so much use it primary to slow enemies down, farm and pushing lanes.

At lvl 11 you should have 2 points in your storm and the elise miracle (Elise miracle is like having a 7th item since its consumed but you still enjoy the effects). So now you can go take soloblue, either the enemies or your own. Once you have blue boff, you can push lanes so easily, and your sustain in teamfights is huge, and also you have clarity. With the enhancements on the boots you even get 25% reduction in cooldown on the clarity.

How you kill the blue boff is like this, first R then use wall to trap the monster, then use E, then u wait till wall is gone then use Q to stun the monster, then when the monster is ready to attack you, you can use E again. Sometimes its necessary to use clarity to do this, but its ok. The clarity will be up again to take the next blue.

So with anivia support you get a support that can halt enemies gank on ADC, a great pusher, blue boff stealer, a devastating wall for teamfights, some dmg aswell and a support that is very hard to kill. I have played a 50 minute game with 0 deads.

The passive of Anivia can also be used to get a kill early on because the enemy will go on you, but hey you bought 180 HP right? So its not gonna happen that they will kill you, what will happen though is that your ADC will get free shots on the enemy, and if you position yourself, so that your egg is under protection of tower or just your ADC, and if your ADC is good enough you wont die, but they will die.
But if you are uncomfortable at turning into an egg just flash away and wait to see if a better opportunity arises next time.

Yeah as i said i wont spend too much time on this guide. If you feel you can do it better just go ahead and copy from mine if you want. To me its just important to get this guide out, since its the first of its kind as far as i can see.
Whether its useful on high ranked games? I dont know. Maybe you can help me with this?
Also i would advice only to follow this guide if you are used to play anivia mid and the support role.