well this build is about this blue bird named Anivia, and is a great champion IF USED CORRECTLY.
with this build u should not have any problems with surivability late game if u play smart, and u will end up with a lot of assists and kills. Anivia is a very intimadating champion (cept for its cuteness O_O) and can turn the tide in a losing match

PROS
great mid solo laner
great stun (if used properly)
nice AoE ultimate
one of the best passives ever
ICE SHIELD!!!!
best rape dance ever
has ability to fly

CONS
very squishy
very mana consuming ultimate (get blue buff)
very slow attack animation
very slow character

so i start off with Sapphire Crystal and 2 health pots.Another way to start would be an Amplifying Tome and a health pot. This will let u get your Mejai's Soulstealer faster, but just be wary of mana consumption and u only get one health pot as well.After that u wanna rush your Mejai's Soulstealer as quickly as possible to start to get stacks on them for rapage :D. Then get ur Boots and this is self explanatory. After grab ur hands on the Catalyst the Protector just to make u a bit beefier and grab ur Sorcerer's Shoes or Ionian Boots of Lucidity but i usually go with the sorcerers shoes for more penetration of course. then finish your Rod of Ages and work on your Rabadon's Deathcap for more AP :D. Then comes Hextech Revolver. Some Anivias dont get this item but i dont understand why u get ability power and spell vamp! works great with ur ultimate. After u can grab your Archangel's Staff for more mana and ap as well OR u can also go Void Staff if they are stacking MR and finish your Will of the Ancients.

Ok now to the topic of the Blue Buff. You should be the one getting blue buff almost everytime after lvl 11ish since with the blue u can farm waaaay more efficient since u can just use ur ult on em and see the gold going into ur wallet. The Blue buff also helps with team fights since u can just keep ur ult on thus having AoE damage, double damage with ur spells, and a slow which helps out a lot. And come on who doesnt like spammin spells? lol

Runes Runes Runes.... OF COURSE u will need Greater Mark of Magic Penetration for magic penetration. Now for seals there are a few choices but usually Greater Seal of Evasion is the best choice since dodge helps out plenty. The other seal runes that would work as well would be Greater Seal of Magic Resist for some Magic defense. Moving on, glyphs its gotta be Greater Glyph of Cooldown Reduction hands down for some CD reduction which is universal since it works well with any champion. Now for Quintessence i perfer Greater Quintessence of Health for health which is always a plus.

now this is important your teamwork has to be good (especially with randoms) since Anivia cant go up 5 vs 1 (lol i did once) u need good crystalize placement as well as flash frost. some tips is if u know they are in a bush throw one flash frost in there, use ur ult put the crystalize and throw a frostbite to teh weakest while your team rips em apart. Another way (and one of the best) is to cut one of them off the rest of their team and rape em. overall its a team game of course so this will make u the bird of prey or the prey of bird o.o

so early game u just want to get as much gold as u can. last hitting with Anivia is somewhat difficult since her attack is slow and has very little damage, but its possible. don't play too aggressive unless they r dumb enough to get in ur range. just harass with ur auto attack and maybe ur frostbite (also flash frost if u can land it) if u get first blood good job :D also use ur passive to ur advantage: lets say u guys r both under half hp u can attack or flash in and try to get them very low and ignite. If u die dont worry :D ITS WUEVO TIME u most likely killed em off with ur ignite but if u did not most of em would likely stay and try to kill u. THEY FAIL u will revive since damage output isnt that strong early game and wala first blood <3.

now ur a boss of the sky (hopefully) and have decent amount of stacks and should be working on ur Rod of Ages or ur Rabadon's Deathcap by now. Just be more careful since u r squishy at this stage and just gank or if u have a lot of stacks just roam around like the boss u are :D. Remember though, even if u have 20 stacks u cant do nuffin agaist their whole team and your by urself.

now this reflects your entire game so far. if u are legendary GG. if u have decent kills u can end this if played right. if u fed ._. (how is this possible) then most likely u will lose D:
U should be getting ur Hextech Revolver by now and its important so ur ultimate heals u (woot) and will give u more survivability in team fights. Ff the game progresses even more (rarely) then get ur Archangels Staff and if even longer finish off ur Will of the Ancients.

this is my first build so any comments will help and if you need me to go more in detail on a specific part then just say on what and ill try to do it asap :D thx for reading and rate if this helps. thx again <3