The biggest fool turns out to be person behind whole thing

I'm looking for stories where the most unexpected person, some loser turns out to be one who organized whole thing, mysterious person who characters looking for or need. .

The Untamed 100%! It's very satisfying.

 Nermeen:

Who ?how ? can you spoiler it to me?

I kind of hate to spoil it because it's satisfying to realize what's happening as you watch it, but (massive, massive spoilers ahead) basically the drama starts with a long flash back to a time when the children from all the main clans (including the leads) were studying together. Nie Huaisang was one of the leads' classmates. His older half brother Nie Mingiue was a fierce clan leader, while Nie Huaisang is frivolous and timid.  In the next half of the drama, the main villain partly causes the death of one of the main characters and also directly causes the death of Nie Mingiue, causing Nie Huaisang to become clan leader. He continues to build a reputation for being timid and useless (his nicknames are headshaker and good-for-nothing) but secretly sets up a series of actions that allow the main character to come back to life and kill the main villain in order to avenge his brother's death. He does a few things subtly to make sure that outcome occurs, but if you watch the drama and don't pay attention you might not realize that his actions / presence are intentional or that he's anything other than a fool.

Love Alarm