This is my first guide, so I'll continue to work on it as I can but I also want to keep it simple as well.

I never saw any real good Nasus support guides out there that didn't make Nasus support just seem like a troll pick. He isn't the ideal support pick, and some people's first reactions are "WTF SUPPORT NASUS!" But I wanted to try and find that secret support nobody really plays, and I think AP Nasus Support is that champion. His off-tank abilities, MS and AS debuff built into his W Spirit Fire, his armor reduction and AOE slow once a Rylias is built all make him a pretty decent support pick. His lane presence is supprisingly stronger than you'd think. At the end of every game I played support Nasus and destroyed in lane, nobodies questioning the pick anymore.

AP Nasus's strength lies not in his multiple slows, attack speed debuff, tankiness, or good AP damage for a support. But in that fact he can reduce the armor of everyone on the enemy team on top of that. In lane your adc will feel like their autos are hitting for true damage. His massive movement speed will allow you to catch anyone on the map for your team to catch up to and finish off.

When is a good time to break out AP nasus? Probably when your a mostly AD team, and have somebody with a CC who can follow up and only slows you land when chasing somebody down.

He's a fun pick as well, give him a try see how you like him.

Pros:
-E&W big in laning pahse. E reduces armor and does good base dmg, while W takes care of the enemy ADC
-With Ult your pretty tanky
-Multiple slows by mid game, to go with armor reduction for whole team
-Q dmg building is just a bonus
-Great peel
-very high MS, I get up to 483 when roaming.

Cons:
-Q's will never get really high
-Prolonged fights will leave you without mana
-Needs rylai's to be a viable support choice over other picks

Soul Eater
(Innate): Nasus drains his foe's spiritual energy, giving him a natural 14 / 17 / 20% lifesteal.

Soul Eater is Nasus early game sustain. Auto attacks regenerate hp.


Siphoning Strike
(Active): Nasus next attack within 10 seconds will deal additional damage. Siphoning Strike permanently gains 3 stacked damage whenever it kills an enemy champion, minion or neutral monster.
Cost: 20 / 25 / 30 / 35 / 40 mana
Cooldown: 8 / 7 / 6 / 5 / 4 seconds
Physical Damage: 30 / 50 / 70 / 90 / 110 (+1.0 per attack damage) (+3 per enemy killed by Siphoning Strike)

Siphoning Strike relies on your ability to kill minions(or champions).

-I don't even worry about this ability. Just use it whenever I can to build up a little extra damage.

Wither
(Active): Nasus ages his target, slowing their movement and attack speed by 35%. Additionally, they are reduced further to reach an extra slow at the end of 5 seconds. If the duration of the slow is reduced, the extra slow will be applied faster for it to reach its maximum at the end of the duration.
Cost: 80 mana
Extra Slow: 12 / 24 / 36 / 48 / 60%
Cooldown: 15 / 14 / 13 / 12 / 11 seconds

-I level up Wither second because once mid game comes around AS is just starting to be built, and the increased slow doesn't hurt either.


Spirit Fire
(Active): Nasus unleashes a spirit flame at a location for 5 seconds. Enemies caught in the area are dealt a burst of magic damage. Additionally, enemies in the area are dealt magic damage each second and have their armor reduced while on there and for 1 extra second.
Cooldown: 12 seconds
Range to Center of AoE: 650
Radius of AoE: 400
Cost: 70 / 85 / 100 / 115 / 130 mana
Initial Magic Damage: 55 / 95 / 135 / 175 / 215 (+0.6 per ability power)
Magic Damage Per Second: 11 / 19 / 27 / 35 / 43 (+0.12 per ability power)
Total Magic Damage: 110 / 190 / 270 / 350 / 430 (+1.2 per ability power)
Armor Reduction: 20 / 25 / 30 / 35 / 40

-Spirit Fire is your what makes support Nasus a good pick. The Armor reduction and damage are nice, but once you get rylias the AOE slow is very helpful, and once you get a liandrys it will be your big dmg source as well. Also helps give your team some nice wave clear late in the game.

Fury of the Sands
(Active): Nasus becomes empowered in the sandstorm for 15 seconds, gaining extra health. While the storm rages, he drains a percentage of nearby enemies max health each second (max of 240 magic damage per second per enemy) and converts 6.375% of the damage done into bonus attack damage for himself until the sandstorm wears off.
Cost: 150 mana
Cooldown: 120 seconds
Radius of AoE: 350
Health Gained: 300 / 450 / 600
Max Health to Magic Damage Ratio Per Second: 3 / 4 / 5% (+0.01 per ability power)
Total Max Health to Magic Damage Ratio: 45 / 60 / 75% (+0.15 per ability power)
Total Magic Damage Possible (to a single enemy): 3600
Total Bonus Attack Damage Possible (from a single enemy): 229.5

-Fury of the Sands also applies the aoe slow from Rylai's Crystal Scepter. This means that they are fairly stuck to you as their hp drains steadily. If they focus you, you have decent enough health to survive a lot of it. Not to mention focusing the support is good for everyone else on your team.

Why go with the masteries, runes and summoner spells I reccommend?

Nasus support needs lots of Movements speed to as to catch enemies with his slows and roam around the map easily. There for MS Quints, masteries, and summoner spells are essential. He also needs plenty of tanky stats to allow him to soak up damage for his team and adc in lane.
Heal gives nasus MS and a Heal for himself and ADC for when your engaged in fights, thats why I like it for my second choice.

Core Items:

Targon's Brace Important for survivability in lane, and late game will be a nice shield for your carries.


Rylai's Crystal Scepter This is what makes support Nasus a decent pick, it AOE slow works well with your spell kit. Will also allow you to do some decent damage as well during the game as well as make it easy for your AD teammates to take down your enemies.

In lane:
Use your E Spirit Fireto catch both enemies standing near each other in the back. If engaged on, W Wither the enemy ADC and use your E Spirit Fire so your ADC can do some real damage to them. If you want to get aggressive, land a W Wither and follow up with an E Spirit Fire so you and your ADC can drop your enemy fast as they will have almost no armor.

Team Fights:
Stay near your ADC so you can W anybody who comes after him and use Face of the Mountain to protect him if the damage becomes to much.
Your E is your best tool in team fights. Charge in and throw it on the ground slowing all enemies for your team to engage on, or throw is as you flee to let your team escape. Its armor reduction and slow make it the perfect ground for your team to fight on.

Q Stacks:
AP nasus doesn't really build Q stacks really high, but having a scaling dmg abilty is still very useful when chasing down an enemy with no life and you need that extra burst of damage.

Tankiness:
Your Ult does damage and gives you bonus health, most your items feed into your off tankines as well, and don't forget you have a passive life steal. Your not an ideal tank for your team, but with your ult up you can provide some decent tankiness to your team.