Akashic Records are items that we can obtain from AR Transmiters by fully RNG.
There are 2 types of Akashic Records, Active or Passive. It's pretty selfexplanatory but basically Active Akashic Records do something when the player uses it. Meanwhile passive ones does something when the condition asked by the Akashic Record is completed, for example "When perfoming an hit" -> When you hit an enemy.
An Akashic Record can be enhanced using others Akashic Records. It can be enhanced up to +2 and it improves the effects given by it.
Also there are the special enhanment which means that the Akashic Record uses exactly same Akashic Records to became "Special", this just makes the Akashic Record looks purple and it gives better effects.
This two types of enhancement can be done in Io (Shiro) NPC.
Akashic Records are categorized from tier ☆ to tier ☆☆☆☆☆. Being 5 stars the best ones and 1 star the worst and most easy to get. 5 Stars has an really low chance to be obtained from a transmiter.
You can check the fully list of akashas ingame in the Akashic Record window. You can also see the differents of +0 +1 +2 and Special type of all Akashic Records on this window.
You can equip yourself on the Akashic Records windows an max of 5 Akashic Records. You can't equip the same Akashic Record multiple times.
For active Akashic Records, you may have not setted the keybind for its use. You can do that on ingame settings.
Usually the priority is getting % of boss damage, then attack speed and then SV regen. The others 2 Akashic Records are usually preference or simply adding extra of those priority effects if you dont have the best Akashic Records for it.