I'v used this build and was very fun to use.

@ murtaghking magic pen and ap are for ad champ? lol unless you mean mastieries, and then i disscuss this in my build, and as far as mana, for my play style clarity is sufficient for the specific reason that i don't cast alot of spells, rather the ones that i do cast are devastating.

@vinnmaus summoner spells are player preference, again i find that tele and clarity are the best for me. also if you read the masteies section you will see my reasoning as well as the alternative option. i find that void staff vs lichbane keeps my ap punching harder keeping the kills rolling in. as far as ranked vs casual, if your good mejais is worth it. learn not to die.

-1 sumoners spells , you need flash and ignite with sion.
-1 why masteries in offense? you are AP not AD, why that crit and 4% dmg? magic. pene is enough.
-1 Lichbane is more important than void staff + you dont use mejai in ranked. its not wort it.
Sorry

sapphire crystal builds into sheen -> Lich Bane

but there is a big thread i want to complain about: sion is very mana-hungry and you don't build any mana regeneration items

+ you have runes for a AD champ

if you change those things i will give you +1

what does the sapphire crystal build into? I'm just wondering.

ty for the catch. sorta put it up in a hurry.

You have 5 levels of Shield at 8