As you know the You&I Update changed how the Inner Ability system worked but it was more than expected.
Inner Ability now uses a new point system (Honor Points) to reset the Inner Ability.
So clicking the green button in the stat window will open the Inner Ability Window.
Now, the first box (the yellow box being unique) states your ability rank, clicking it will lock the rank but increase the honor require to reset it. (1st picture being no lock and 2nd rank being locked)See with the picture on the right resetting the inner ability has gone from 100 -> 5100 Honor for locking the rank (I'm not sure if the resets can still rank up the current rank)
The thing is you cannot lock a inner ability if you don't lock the rank because all 3 lines are the same rank. (Yes locking is free)
No Lock would be resetting without locking the rank (which risks lowering the rank by the way) * you can't lock rare rank or rare lines*
PS. I got this after a few locked rank resets :D (it's 17% critical chance) *too bad it's on my Zero :(
Also forgot to mention, Aswan Medals that drop from mobs now give 3~10 Honor each (which is pretty low) and with Aswan closed I expect a revamp on Aswan so we can get honor more easily. (If not well then gg)