ATMA ... Please explain?

So, I have seen so much talk of this atma business. I am starting to understand more about end-game ... ilvl, hard modes, and whatnot, but after searching pretty extensively, I am unable to get an actual definition or basic guide as to what atma actually is. I know bits and pieces about it but overall, I have a lot of questions. Seems like it's an item(?) that there are 12 of that involve grinding fates ... Please explain?

a) what is Atma?
b) What does it actually do/what's it for? Held item? Equippable?
c) how do I go about actually getting them? I know it involves fates, but is there anything else to it? Which fates? Any of them?
d) Why break my back grinding Fates to get them? Are they that important?
e) Is there any kind of minimum ilvl or quest prerequisite?

Thank you for any help.

a) atma weapons are the relic zenith upgrade ( stats are same as zenith)
b) ???
c) u need 12 atmas to upgrade... each atma is dropped from fates in specific areas, not specific fates! for example atma of the maiden is dropped in central shroud by any fate... oh and RNG is involved here so prepare to waste your time :)
d) u need atma drops in order to upgrade the weapon
e) u need any zenith weapon equipped to have a chance (lmao) to get an atma and ofc quest "Up in Arms" which u can unlock in an npc near Gerolt.

P.S: if you like grinding do this otherwise do it later or never!

Thanks for your help. Sorry, I guess I didn't know enough to know how to phrase the questions, but I got the jist of it.