Not Updated For Current Season
I've been playing with morgana for a long time and became pretty good with her. Almost every game i play with her turns into a win even when it looks horrible.
Zonya's hourglass combined with your ultimate destroys teams if you do it good.
The skilling order can be changed depending on how the game is going. If you are against a strong caster in mid you will want to take black shield at level 5 so you can kill him without getting stunned at lvl6.
If there is no point in harrasing the enemy lane (they outheal you) or you want to play defensive and just want to farm in the start, get tormented soil at level 1,3 and 4. Once tormented soil is level three you can kill the caster minions with it when they have full hp.
Use zonya's to run into the enemy team (with black shield on so they cant stop you). When you are in the middle of them, pop your ulti and hit zonya's. (ofcourse dont run in alone your tank should draw some attention so you can do this). When zonya's goes off you can walk away if needed and your black shield will be back soon.
This is the reason I get zonya's as 1 of my first items being able to become Invulnerable for 2 seconds is so powerful and can save your life very often
When you engage your enemy's early game:
Start by harrasing your enemy to bring them to around 60% health(if they are squishy) or 40% when they have some higher health / MR.
Next activate your ultimate, usually when you do this they will try to back. If they do just follow them. If they attack you put up black shield and try to kite them without going out of range for your ultimate. Just before the stun of the ultimate is going to go off put a tormented soil where they are standing in the direction they are running. Tormented soil decreases magic resist making your ultimate stronger when it goes off.
They should be stunned on top of your tormented soil, wait for a second and then snare them so they will be close to the full 5 seconds on top of the tormented soil.
If you have any questions or think some things can be improved, please comment :)