Seriously? Worst decision ever.
The only possible reason I could see for this banning was to attract new players, of course as usual with game developers, it's okay to attract new players at the expense of old ones.
Without Olcadan's about half the symbols in the game become completely unplayable, and Order, which is the most overpowered symbol in the game right now becomes even stronger, because they're one of the ONLY symbols that now has any way to deal with problem foundations. So now everyone else has to deal with 2/3rds of their staging area being constantly Chinese Boxed and PM'd all game long. Awesome.
Chester's, yes, it's overpowered, but at worst it needed an Eratta, the life gain was unnecessary, but a lot of those symbols (mostly ALL) need some form of negation, or they become terrible. I understand you don't like foundation wars, but without negation the game becomes all about who gets their condition first without any semblance of strategy. And it removes a huge amount of interaction between players from the game. Negation is a good thing, overpowered cards aren't.
Lord of the Makai is an enabler, sure, but the real problem with it was Defender. Defender was the problem. I have three, they were MUCH harder to get ahold of than my LotM's and I would not have even felt annoyed if they got banned. Also if you want to ban enablers why did you leave Shinobi Tradition around for so long? It was twice as bad and a common.
Basically what you've accomplished instead of better balancing the game is turning the game into a fight between Order and Water to see who can pull off their spike or ira spinta recursion first. Fun.