Hello evryone this is my first build.

EDIT:
1: detailed more items
2: detailed more invocater spells


Skills

i know my skills arent right i mean by this that it is your choise

Feel No Pain - Sion has a 40% chance to ignore up to 30/40/50 damage each time he is attacked. The damage reduction is calculated before armor benefits are taken into account.

Cryptic Gaze- Blasts a single enemy, dealing 70 / 125 / 180 / 240 / 300 (+100% of ability power) magic damage and stunning for 2 seconds.

Cooldown 12 / 11 / 10 / 9 / 8 seconds | Cost 100 mana | Range 550

Death's Caress -Sion surrounds himself with a shield which absorbs 120 / 170 / 220 / 270 / 320 (+100% of ability power) damage. If the shield is not destroyed in 10 seconds, it will explode, dealing 120 / 170 / 220 / 270 / 320 (+100% of ability power) magic damage to surrounding enemies.

Cast again after 4 seconds to manually detonate.


Cooldown 4 seconds | Cost 70 / 80 / 90 / 100 / 110 mana | Range 1

Enrage - Toggle: Increase Sion's damage by 25 / 35 / 45 / 55 / 65, and he gains 1 / 1.5 / 2 / 2.5 / 3 maximum health per kill.

Cost 6 / 8 / 10 / 12 / 14 health | Range 1

Cannibalism - Grants Sion 50 / 75 / 100% lifesteal and 50% attack speed for 20 seconds, additionally Sion's attacks heal surrounding allies for 25 / 37.5 / 50% of damage dealt.

Cooldown 90 seconds | Cost 100 mana | Range 1


Masteries

This is more your choise i prefer to play with exhaust and ignite

ignite ---> good against lifestealers
exhaust ---> if they try to run away (hahaha come here you little teemo i promise i won't
hurt you :D)
ghost---> extra running speed , should be picked with flash
flash---> handy to run away
clairvoyance---> is not a spell for you leave this kind of spells to soraka or support
champs
heal ---> can come in handy in team fights or ganks with a ghost your still alive
clarity ---> won't need because of the Archangels Staff
Items

You see that the boots are missing .

Sandals of Mercure : if the other team got heavy stunners (ryze,malzahar,..)
these boots can even make malzahar his ult shorter .
Boots of Mobility : If the other team got no stunners or slowers (rather small chance)

Archangels Staff : u will need a lot of mana for your cryptic gaze and your shield .
it gives a pretty good amount of AP too

Void Staff : is optional i picked it because it gives a lot of AP .

Mejais soulstealer : is optional too but only pick it if you are SURE you get much
kills and won't die much

Stark's fervor : is another optional item . gives lifesteal and att speed only pick it if
your team doesn't got it yet


End

this build has been tested by a few sion with a good score