when in doubt pick Morgana

if you have no idea who you want to play and don't want to be countered just pick Morgana because

1. her counters don't really counter her
2. all you need to do is farm and snare
3. she is low risk medium reward but she is not a fool proof plan
4. she wont make a huge impact in the game
5. she isn't unstoppable
6. her cooldowns are her weakness but heres why i think Morgana should be the pick if you don't know what to play in mid top or support her counters are just to scare her from going all in but even then all you really need to do is farm and roam, the best counter i can find online is talon but Ive faced multiple talons as Morgana and they really aren't that big of a deal since your spell shield makes you immune to slows and a reasonably big chunk of talon's damage is because of slows, as soon as you see talon use his rake just spellshield yourself, it will still hurt but that's nothing your spellvamp cant handle and even if he uses his e first that just means he screwed himself and got himself into a prime spot for your ult and if he tries to ult out he cant go invisible when he has a chain on him, just snare him and watch his life bar slowly drain. and if you do find that opponent that can challenge you in a duel you really don't need to duel, all you need to do is farm and be safe, don't take a risk just try to harass with snare and kind of line your pool to hit back minions and the enemy champ but if the enemy can duel you don't take the fight, just farm and roam she cant 100-0 unlike popular mages or etc but her damage will chunk somebody to either get out of lane or to make them play safer if you land a snare and make them take a full duration tormented soil, plus late game your snares can make a difference in teamfights but rarely do you get a pick if you snare someone but then Morgana isn't the foolproof plan i may or may not have summed her up to be, she wont win your games only you can win your games her impact in the game isn't the "you land a snare gg we win" her strength is in a war of attrition, she wont shine in teamfights but she is a huge help she isn't unstoppable either, she can easily be beaten if you can dodge her snare and take minimal damage from her pool but even then that's easier said than done and her cooldowns, even with 45% cdr she cant spam, her snares might feel like 3 years but her cooldowns also feels like 3 years especially in teamfights

tl;dr: Morgana is a great pick if you don't know who you want to play but she isn't a foolproof plan to win the game