Morgana mid is extremely fun to play and makes for excellent team fights both mid and late game. Bear in mind that she is not a very good aggressive pick and is better played defensively and slowly, trying to catch enemies out in bad spots with your CC.
Roam as much as possible and help your jungler as your kit allows for excellent ganks.
Morgana is an extremely popular pick but certainly not popular in the midlane which is great for us since some players might not know how to play well against a morgana midlane which we can use to our advantage!

CORE:
Liandry's Torment, Malignance and Rabadon's Deathcap: Synergise well and give you a tonne of damage. Liandry's Torment burn is amazing with Tormented Shadow and Malignance makes Soul Shackles feel great and a lot more impactful. Rabadon's Deathcap is a great way to end a build with it's crazy damage increase.

OTHER ITEMS:
Zhonya's Hourglass: Great for safely going in and using Soul Shackles.

Horizon Focus: Works really well with Dark Binding since the skillshot is over 600 units in length.

Void Staff: Extra magic pen is always nice.

Blackfire Torch: I like it for the extra burn damage so it is good against comps where there is a lot of sustain or to beef up your damage against tanks. Due to the passive, be sure to get in and help out your jungler with objectives and remember to roam as often as possible!

Rylai's Crystal Scepter: I love this item for it's passive which makes it a great option for teamfights due to the slow

Morellonomicon: Great into heavy healers

BOOTS:
Sorcerer's Shoes: the usual for magic pen and damage.

Ionian Boots of Lucidity: extra ability haste means more Tormented Shadow spam.

*This is a 'for fun' guide and Morgana is probably not the best choice for climbing as a midlaner so be aware of that. *

Thank you for clicking on my guide and have fun melting away your enemies health bars!