Cita:Somewhat more organized details:

Around Step:
* Basically like it was in Graces, you evade attacks and damage is reduced to 1.
* You also gain SC and BG.

SC:
* The blue gauge below your HP.
* When you use an attack the SC consumed is dependent on the strength of the arte.
* You can chain attacks up to a maximum of 4 times, but if you have SC left over you can start the next chain of attacks.
* Recovers when you wait without acting, but you can recover it more quickly if you block or evade attacks, and probably various other unmentioned things. How long it takes to go from empty to full isn't specified, they just say a "short time".
* The maximum is 100.

BG:
* The number next to your HP and SC.
* Increases from defensive actions like guarding and evading.
* Can be used for special effects like SC recovery and blowing away the enemy.

Shushin and Baishin:
*A contract between two Tenzoku rather than a Human and a Tenzoku. The Baishin must act with the Shushin, who is the master of the contract, but the Shushin gains access to unique powers. It appears that it's rare now, but used to be more common long ago.

Other Stuff:
* Weakness multiplier system is back.
* Unlike Graces (and more like Xillia 2) we seem to have both resistances and weaknesses.
* The characters are paired and that thing in the center has corresponding elements. The shot with Slay, Miculio, Alisha, and Edna has Water and Earth, and Slay with Lyla has Fire.
* In a screenshot in the magazine Miculio and Lyla are entering into a Shushin-Baishin contract with other. I think that suggests that this pair/contract/fusion system thing in the battle system could be Tenzoku x Tenzoku in addition to Human x Tenzoku.

Cita:The contract thing hasn't been explained in detail yet. It likely relates to the "Fusionic Chain" part of FC-LMBS, which also hasn't been explained yet, so it probably has both a story and a gameplay purpose.

We know Slay can make contracts with them because that's said to be one of the main powers of a Doushi. They haven't said why Alisha, and likely any other human party members if we get more, eventually gains the ability to see them and possibly make contracts with them, assuming the main feature of the battle system does relate to contracts.

Shushin-Baishin is a contract between Tenzoku, where one lends their power to another. Based on the screenshot and the description, it's a lost/ancient ritual that's uncommon in the present era, and only Lyla seems to know about it.

It wouldn't make sense if you paired someone to a character and were stuck that way for the entire game, so I suspect that either one person can be in multiple contracts, or it's possible for the master of the contract to end it and form a new one if they desire. Forming multiple contracts might be what makes Slay special, as it's said that a Doushi reaches the height of their power if they manage to form contracts with Wind, Water, Fire, and Earth. Maybe a normal human can only form one contract at best, and that's if they can even meet the requirements to see Tenzoku.