Ares 90 first. Then farm for Laliah and discbombs (high level Milsaadi drop them, but make sure they come w Custom Magazine upgrade Aug) this will be stronger than the Ares 90. And is customizeable so you can use the ME-M Missiles which are good for farming Yggy
My suggestion was actually
not getting the Ares 90 first (or potentially at all) - contrary to the typical suggestions. Getting the Lailah is as easy as getting the Ares, and unlike the Ares, will quickly be able to break parts off Yggy extremely fast. The faster you can farm Yggy, the faster you can upgrade and do other things.
It's also super survivable, so while it wont be one shotting things, it should be able to kill most things even while modestly geared.
I view the Ares 90 -> 60 skell progression as something that predates the knowledge of the appendage crusher builds. Without those builds, the Ares makes total sense. With them, the Ares isn't really needed anymore. Fine to get if you want the skell, but not needed otherwise.
Okay so, to summarize:
Get diskbomb Laliah setup (What the hell is that? Laliah is the name of the Skell and diskbomb is the name of the Art or the weapn?) Where do you get a Diskbomb(s)?
Then, I should go for the Ares 90,
THEN, I should go for ticket farming (killing the Global Nemesis Telethia), and buy my Aguments that way(?).
Is that all correct?
Lailah is a skell, yes. Diskbombs are a sidearm dropped by Misaldi Savages slightly south and down the mountain from 513 (right at the sharp bend). The goal is to get ones with MAG-MSL on them and then upgrade those traits. In addition to doing good damage, they allow extremely fast GP gain. Combined with the 6k GP of the Lailah and an OD that reduces incoming damage, constantly heals the skell, and makes it immune to debuffs, you're more or less left with a skell that is constantly in tank mode.
The M-Missiles (ME & SA variants) are shoulder weapons that drop from pugaliths. The best bet being the Judge Pugaliths in the Ganglion Antropolis. (Definian downfall quest chain to open that area.) They target every single appendage on a target. Combined with appendage crush augments (crush.append xx), this allows the skell to break Yggy's parts quickly and abandon to collect them. I once again refer to
my average run on Yggy. The Lailah wont be capable of doing it quite that quick**, but it'll still be faster than an Ares 90. And use basically no fuel while doing it.
**A Lailah with Inferno armor and the ME M-Missiles will be able to, but I'm referring to a stock Lailah.
Edit: As for what a diskbomb Lailah is like, I refer you to
Yggy and
Pharsis. You'll notice the diskbombs quickly boost the GP which is used to stay in OD. Obviously this isn't a stock Lailah, but the diskbombs are all it takes to enable the constant OD.