War Build > STR or VIT

[Exstal]

But how long does it take to get a full set of Myth accessories, or its coil equivalent?

It takes 10 WP runs to cap your weekly myth, and that will also get you 1000 phi tomes that you can spend on animal fat/peacock ore.
In a couple of weeks you will have enough mats to craft an i70 item. Between two and three months for the full set.
Pretty much the same time you need to get any of the i90 accessories.

On top of that you need the money for the melding but you can start with the easiest and cheapest three slots and then slowly save to meld the 4th and the 5th.

Alternatives? Spend the same amount of phi tomes to get a secondary STR set. Not really worth if you consider the hassle of switching gear set and the HP loss.

The bolded part i just didnt get it. Only the fifth slot has 8% success rate, and ideally should be melded with VIT materia 2, which is cheap.
Do you know how melding works in this game?

I can't even get 4th slot on my Astral. It's more, I don't want to spend money on something that I'll replace with something better.