Okay for those who don't know what RNG stands for it is Random Number Generator, which is fancy talk for the thing that decides what loot drops.
Now RNG exist for the sole purpose of making content last longer, if we ran coil and beat it once and got our loot immediatly not much incentive to do it again right?
The reason RNG sucks is that because it is in fact RANDOM you could get one guy who gets every piece of loot his first try and then another who will never see it at all.
This my friends is the idea (which by the way is tailored specifically for this game):
So one of the many good things about this game is the Armoury system, you can be any job whenever you want on your one character. You are probably wondering why I brought this up but it will be explained right now.
I propose that Coil drops Tokens similar to how the Extreme primals do, except a little bit different. The idea is that you beat Turn X Y number of times (open for interpretation) until you accumulate enough Tokens to purchase whatever piece you want from that Turn. So let's just call it 3? Clear a turn 3 times and you earn yourself a piece of loot from that turn.
BUT MAZI IF WE DO THAT THEN COIL WILL BE DEAD IN 3 WEEKS!
That is where 2 factors come in. The first being that some turns have multiple pieces of loot for the same job so you might actually need more then 1 piece from it. The second is that you will still want to run coil for *drum roll* YOUR 8 OTHER JOBS! Now Yes you can argue that some jobs share loot or that you don't even care about half of them which is all valid points. However the amount of time it will take to get all of the loot should be long enough for them to spew out more turns n whatnot.
Well that is my idea, feel free to throw in your two cents.
TLDR: Luck bad, Skill good
Oh forgot one thing, some masochist are going to argue that luck is "Fun" and for that I say. Make Coil drop a mount or some housing stuff ya know something that if it drops you are like OH SWEET AWESOME but if it doesn't then whatever.
Edit: With this idea coil will still drop loot as is just the tokens aswell to safeguard against bad RNG.
Edit 1/15: So just skimming through the many pages this thread now has (nice work team) there are some people coming up with some quality ideas:
And then I see others who are claiming that Mythology IS the token system.
And then I also see the "RAIDERS ARE SO ENTITLED GAH D:" people.
and then I see the "takes the fun out of gear if you know you are going to get it" which kinda contradicts the Mythology concept since that is exactly what it is doing.
But anyway as some people have mentioned:
You sir I agree with completely.
This is also a good point, they have ALOT of drops for such few bosses so that could be making things worse.