I have three villains. The first two are important, but pawns of the third villain's plan, though we don't see the third villain until the very end. He was manipulating them, setting breadcrumbs, etc. Later in the story, after second bad guy's defeat, the main character&co. find clues, realizing that they were wrong about the previous villlains. Things have been adding up little by little, but now the puzzle pieces are truly beginning to fit together. I have a bunch of the basic plot notes jotted down, but I'm stuck on how to add this extra flare to it. This elaborate plan. Is it because I'm lacking just that? And I need to know what the character needs to do in order for it to fit into the plot? Has anyone watched Death Note? It's similar to when we think Light Yagami is captured, but we later find out that he had made this cunning plan was to actually get captured. The character knows something that the audience doesn't, having made up some intricate mind-blowing plan. Hopefully this makes sense :/
I think the key to adding the 'flare' (as you put it) is to really engage the readers in this process of following the breadcrumbs. Rather than focus on the actual 'Ah-ha!' moment, put a lot of effort into the earlier part of the story and setting up the pay-off. Give the audience enough breadcrumbs that they feel like they might know what's going on, but at the same time leave important gaps. That way, when everything is finally revealed, it will have a lot of WOW factor. You just to be careful that this final reveal doesn't seem to just come out of nowhere, but actually ties in with all the clues before. That will make it much more satisfying when the answer is found. To use your example, in Death Note we have a sense that Light is planning something to use his imprisonment to his advantage, but we don't know what. Honestly, it seems like the situation might be a little to hard for him to wheedle out of. Then, when he pulls it off and reveals his master plan, the audience is so amazed at his ingenuity, it immediately adds this wow factor. The situation you are talking of also reminds me of the set up in the British TV show, Sherlock. In the first few episodes, it is hinted that there is someone controlling the antagonists from behind the scenes, but this shadowy figure is known only as Moriarty. When all the clues come together and Sherlock comes face to face with Moriarty, it really has a great sense of the WOW factor because of how the director has set it up in previous episodes. So in re-cap. Make sure to properly set up the pay-off when the MC finally realises who the true antagonist is. And make sure to hold back enough info that the final pay off really becomes a great WOW moment, without seemed out of sync with the rest of the story. Anyway, I realise I may have rambled a little, but I hope I helped.
Don't worry about extra flair (sic). That's a matter of developing your writing "voice". If you're thinking of a "twist", don't, unless it falls naturally from the story events. Twists are overrated, and all too often make the writing look as contrived as it is. Just tell a good story. If it doesn't come out right in the first draft, you can tune it and amp it up, possible by raising the stakes. But first, get the story you have on paper or bits.