Hi everyone.
First of, know that english is not my native language. I hope this remains easy to undertand. This is also my first build here.
I've been playing LoL for a couple of months now, and one of my favorite champ is Morgana. I started by looking at some of the builds on this sites, and then tweaked them. After trying a lot of her build posted, i decided to post this one as it lead me to many wins and better games. Many consider her as a bad champ, and i can see why. Morgana will hardly ever get the most kill in a even match. She does not have killer moves like Fidd's ult, but guess what, she takes a support role. If you play her, be ready to get a lot of assist or KS. However, when build and played correctly, she will definitely change the tide of the battle. Teamed up with a fighter, the ''duet'' is fearsome.

First, it's important to note that i adapt my builds a according to who I'm facing and who are my allies. I usually chose between a tad cooldown reduced build (when team'd up with assasins) or a Nuke oriented build. She then has the most supportive role and will end up with over 10-15 assists if both player do well. I will however aim this build towards the nuke part of Morg). I also aim my builds towards being as constant as possible, therefore no soulstealer are included in them.
I think Morgana relies a lot on skill of players, game context and a lot of decision making. This has influence on item bought and skill leveling up. I will go with my most AP build in a even match.

I will keep updating this guide (esthetic) and work on some aspect and explanation further on, as i am not quite satisfied yet, but i wanted to publish this.

Pros;
-Snares like hell, (DB ofc; also, echo of ultimate stuns, helping pursue)
-One of the best support (shields, stuns)
-Can shoot through wall with Dark Bind!
-Can sometime escape bad situation with Dark bind and Black shield as def against magic.
-Adapts a lot to enemies.

Cons:
-Can hardly handle 2 enemies at once on the field without mobs
-Relies a lot on ult to kill on her own.
- Slow movement..
-Fragile

I go for total mana regen as in my item build i prone only dmg (AP & magic Pen)
You can usually not oom after lvl 10-12 if you use clarity as spell. This with Morg's passive 35% spell vamp makes her real good at stretching her presence on the field for those extra golds when it's possible. I guess someone could go half magic Pen/ mana recovery, but i have not tested it out yet as runes are kinda expensive and i play mostly mage so i can use same rune sets in order to buy more champ's.
I also go with mana regen over 5 sec instead of mana regen/lvl because i prefer having a better start than a superior end-line mana regen because i never have any problem with mana at those stage of the game.

This mastery set is my favorite though some variant of it can apply; I.E : i use exhaust so i have Cripple; if you wanna use Ignite for more dmg and help against hp recovery (fidd, vlad etc). This mastery set is also great for other mage; I mainly play them and just tweak it accordingly.

Now here's one of the tricky parts of Morg that asks quick decision making and good understanding of the move's synergy. I'll start by this pretty obvious sequence;

-Exhaust : ( minus speed and MINUS MAGIC RESIST with the mastery)
-Tormented Soil quickly followed by a
-Dark Bind
-Pop Ult if available; often wont kill him on the first hit, slows him again
-Attack once or
-Run after your prey to keep him within range of ult (if used)
-Echo of Ult hits (sometimes kills) and stuns him
-Either attack or Dark Bind (cooldown should be over) This usually kill him in addition to snaring em again

This is to maximize the time spent and damage in the AoE of Tormented soil. It deals A LOT of dmg when executed that way, though it is a lil tricky. The opponent is pretty much idle during this too if you avoid being in range of his Phys. Attack.


Second sequence is what i use if prey is elusive or if im not sure of killing.
I see it as a way to make a sure nice amount of dmg without removing ALL kill chances.

Dark Bind
Tormented Soil
Soul Shackle if available
Next is either a phys attack or strategic character movement.
Dark Bind again (since used first, cooldwn ends earlier than in 1 st sequence)

I did not include Exhaust in the second sequence because it asks for judmgement based on context; Obviously placing it first will increased dmg of Dark Bind, and makes the skill shot easier, but i always feel like it's wasting the mvmnt speed reduction since it's followed by a snare. I this sequence, I'd rather Dark Bind him, close in a LITTLE if needed, then exhaust and quick Tormend soil. This way he stays in the AoE longer and has magic resist lowered for the whole time to increase dmg. Of course you can always wait for later in the sequence as it is not essential to exhaust him early; if you wait, you will

Bind
Soil
Exhaust
Ult;
etc

That way, he will most prolly not be able to escape the echo, which snares allowing another bind and soil.

Yet Another sequence is

Dark Bind
(move in a little if needed)
Exhaust
Ult
Soil
(attack if possible)
Next bind , echo of Ult, etc etc

This may seem similar; one important thing to note however;
Morg's Ultimate reduces movement speed, and it stacks up with exhaust
This sequence allows increased ult and soil damage (- magic res) and reduces mvmnt a whole lot.

In all sequences, you can place your black shield where you like it; i do it either before closing in (IE before any other skills) or after poping the ult, as you'll obviously be following him for the echo).

Also, i did not include the Death grasp active ability. I usually place it where i wrote ''attack''.

No big science behind it honestly; you just need a good understanding of the character and you will be able to pursue & snare to death like no other character.

I never swap the three first items (Doran's ring, mana potion, sorcerer shoes)
as i believe they are excellent stepping stones to the rest of the build.
After is where i start to adjust to my opponents champs, etc.
I have not included any Elixir of brilliance that i buy almost everygame, because i almost never buy it at the same time.
I get one really often after the sorcerer's shoe. The 20-40 AP boosts for 4 minutes is to be reckoned with early game, and cost 250 gold, which i have spare after my first back sometime when buying Sorcerer's shoes. I buy about 2-3 in a game, but i would usually prefer not buying one if i have 460 gold, and go with the longterm amplifying tome instead (which is recipe part ofc)

I adapt a lot the purchase order past the first Blasting wand accordingly to;
-opponent's champ
If i face enemy with Magic Resist (for instance, Kaiser) i will go with a early Void staff
If it's not the case, i will go with early stopping force, deathfire then Deathcap

-Game i am having so far (number of kills, aka amoung of gold)
Around the second time i go back 2 town, i sometime have a lot of money. Therefore, i sometime delay the deathfire grasp, even skip it if i can afford the later items in the Purchase Order.

There is some option here.
I usually go with clarity and Exhaust. Clarity, with the mana regen is sufficient to have a great mana pool that assures me not to run out of mana after lvl 15, even in longer fights. I like exhausts because it stacks uo with Morg's ultimate movement speed reduces, and with the cripple mastery it diminishes enemy Magic Resist by a tad.
Exhausts also helps securing that echo from Soul shackle, and helps Morg poor movement speed.
I also like to use Ignite. Other than bringing a bit more damage, it's a great way to cut enemy life recovery by half.
Of course, Flash is a always a good choice.