If there are only 5 medals per Keyblade, how are assists used to benefit health stats and bonuses? (Since There are five assist cards, how many 'assist' medals regarding health can be equiped? Or do medals serve as both Attack and Assist at once?)
No more worrying about an Assist deck in Unchained! Which I guess is both good and bad?
Unchained introduces a new feature called the "Avatar boards", which contain not only outfits for your avatar, but also stat boosts for HP, AP, and Deck Cost (to use more powerful medals). You can redeem these with Avatar coins, which are obtained by fulfilling specific requirements in each quest. So instead of having to worry about the best cards, you can just go through the boards and pick and choose what upgrades you want to get.
As for Lux, In X[chi] where it is obtained from all the different enemies, Unchained uses Lux as EXP for leveling up instead! Also, Lux EXP in Unchained is obtained not by how many enemies you defeat or how powerful they are; rather, it is determined by how many hits you are able to land on them.
There are some medals such as Riku KH1 Ver and Wakka which are more common and obtainable early on in the game and are fairly weak but have abilities that hit enemies multiple times, allowing you to get a lot of Lux with little effort~
Do the Keyblade stats work the same in mobile as they do in Chi? (Ex: The multiplying bonus for Keyblades if your cards come out in a particular order)
Here is Starlight as an example:
Like in X[chi], Keyblades in Unchained comes with their own unique set of attributes, such as Starlight being better suited for all medal types and Treasure Trove being better for just Power types. The 5 slots in each Keyblade also have their own stat bonuses, which are upgraded along with the Keyblade. If you place a medal into a slot that matches the bonus it provides, it will obtain a power up.
Also, unlike X[chi] where your cards are utilized in random sets of 3, the medals you use in Unchained are used specifically in the order you place them in the slots, moving clockwise from the top.