BLAZBLUE CROSS TAG BATTLE Es BASIC COMBOS【BBTAG Es 基礎コンボ】 

Wrong, filthy weeaboo.

like a tokyo ghoul finisher

Na it works with others as well. You just have to get the timing right. I´m using Es and Yang as assist for example. If I do my 5AAA > 2C > 214CC > 5P then the assist still connects and you can confirm with Es 5B. For Yang I have to dash a bit with Es since Yangs 5P assist resembles a 214AA

Anime notation.

You may have figured it out already since this post is a week old, but just in case, they represent directional inputs as represented on a numbad. So 4 would be left, 6 right, 8 up, 2 down, 5 no input, etc. Hope that helps :3 edit: there are plenty of reddits groups, discord channels and all that who would be much more helpful than me if you needed anymore information for anime fighters.