C: The Money of Soul and Possibility Control/Fridge

Fridge Brilliance

 * The Black Card is the most prestigious eh ?
 * Scorched Earth, Freeze Out, Poison Pill, Pac-man Defense, White Knight, Angel, Insider, Overheated Economy, Mergers And Acquisitions and Cannibalization are just some of the deal attacks used so far. And you thought the attack names were Gratuitous English!
 * Likewise for the "*flation" attacks, given that attacks decrease the value of your opponent's assets.
 * You enter the Financial District and battle with money made from your future. Every trade you do is a bit of your future. You're trading futures.
 * Mikuni owns more Assets than other people (three) - well, he is particularly wealthy (approaching Uncle Pennybags even!)
 * Mikuni says "The world is taking Midas Money for granted." When you consider the effects of introducing Midas Money are the same as printing money...
 * Completely undercut by the fact that
 * In episode six, when Sennoza was flirting with Mashyu, Kimimaro was put off by it. Now, one person can say that he was jealous. But, after watching episode nine I realized that Kimimaro was really acting like an overprotective father.
 * How do Entres see their assets when they're incorporeal? By covering their eyes with the Midas Credit Card, Entres 'blind' themselves to the long-term implications of their actions on the future.
 * Anime's no stranger to villains who preach the necessity of sacrificing or outright destroying the present for the sake of the greater future good and heroes who insist on focusing on the here and now (must protect friends!), nor are stories in general. But [C] inverts this dynamic with a villain obsessed with protecting "the present" no matter the cost to the future and a hero who insists on taking the longer view.
 * Since the Financial District allows the future to be mortgaged for financial power in the present, reversing the process restores Japan's future but removes Japan as a center of financial power (as shown by the fact that the restored Japan doesn't even have its own currency, using USD instead).
 * The logical conclusion is that by overthrowing every Financial District, communism would be instituted.
 * During deals, if an entre is injured, they begin to spout Midas money... That's right. Blood money.
 * In the end, the 'higher ups' inexplicably give Kimimaro a black card out of the blue so he can oppose Mikuni. Why? Because they're in the business of selling loans. Mikuni's methods -- essentially, going so deeply into debt that he can't possibly repay -- are bad for their business; Kimimaro's intention (running the press backwards to repay all the loans) is what the higher ups want to happen.
 * The 'C' stands for 'capitalism'. The "higher-ups" are following the Subjective Theory of Value introduced by the Austrian economists.

Fridge Horror

 * In episode three Jennifer was surprised to hear that a man had disappeared and no one could remember him. Now in episode four we find out that if you go bankrupt in battle everything the money gave you is erased from existence.
 * If you are indeed involved in futures trading, you've basically entered into a contract where you have agreed to trade your future for a fixed sum of money up front. The thing about futures contracts is that the asset is always transferred at a later date, so even if you keep winning, will there come a time where you have to pay the piper?
 * The deal isn't like "futures trading", though (at least if Masakaki is to be believed). Rather, it's a cash loan with the Entre's future as collateral. Not to say that's not still scary.
 * Mikuni uses Midas Money to buy Japanese government bonds (debt) and bail out the companies of fallen Black Card Entres. This is all good until you realize introducing Midas Money into the real world increases the money supply, thereby devaluing the currency - he's effectively stealing billions from everyone who owns Yen. Of course, this may be his plan from the beginning.
 * This is an effect that most of the movers and shakers in the series are well aware of (Mikuni and Jennifer's organization both). It's not a stretch to assume that the added side benefit of winning by small amounts is releasing smaller amounts of Midas Money into the real world in a controlled manner. On the other hand, mitigating the effects of high-powered Entres going bankrupt is something that even those who haven't studied economics can understand, so Mikuni's actions on-camera tend to focus more on that.
 * This also means that if Mikuni were to ever go bankrupt or even just lose, Japan might collapse.
 * It's gone from might to definitely after the events of episode 9 where we see the effect it has on Japan when Mikuni loses twenty years of his future.
 * The collapse of the South American and South East Asian financial district led to the Caribbean Republic and Singapore getting Ret Conned in itself is nightmarish. Given the state of the Tokyo as shown in Episode 8......
 * The cause of the Financial District collapse that deleted the Caribbean Republic was the Lehman Crisis. The risk from interconnected financial markets is scary enough without one of those markets being able to erase you from history when bets go bad.

Fridge Logic
See here.