Fastest way to kill Earth Eater?

[Chaos]

I'm wondering what the fastest way to exterminate those Earth Eaters is. Preparing myself for the Ultimate Lair, so I want to exterminate as many monsters as possible. Earth Eater will take forever with my current setup, though.

[Da_Cloud]

Never quite made it to that fight myself so I can't really tell you any good strategy that worked for me.

What I figured out though is that the ability Beat down is your biggest friend during the end game and I figure having at least 2 of these on your attack oriented schematics really help out. And be sure to buff up your remaining schematic on the defensive side, because as you know those chocobo/earth eaters hit really hard. My personal setup during the endgame was having 2 main attack schematics that were buffed dealing as much damage as possible and 1 defensive schematic with some low cost abilities to keep the stagger going while the rest was re-charging.

Also the combination of the ability Heavy slash with the thief glove accessory (or what it was called again? the one where you can steal debuffs when using heavy slash) works well to take over the buffs earth eater can cast on himself.

For the rest it comes down to memorizing its patterns so you can effectively block his attacks and directly go back into attack mode to pick up the stagger bonus for attacking right after an attack.

[Chaos]

Too late. I skipped the farming and killed the Omega version in the Ultimate Lair last night. Was easier than I expected given my trouble with the normal version. I streamed the Aeronite fight and the Ultimate Lair on the FFT channel. I'll stream the final day and the ending tonight (kinda wish I did this before the FFXV release).

My schemata were the following for most of the farming and difficult content.

Quiet Guardian: Depending on the situation, I would equip accessories for either 100% physical or 100% magical resistance. Abilities were Imperil, Deprotect and Beat Down. Beat Down, in combination with Chaos's Revenge, proved to be pretty efficient for staggering.

Spira's Summoner: This is an extremely overpowered DLC schemata since it comes with an overpowered version of the spell Elementa. I used a sword with 900 STR & MAG dropped by one of the Last Ones. I used a DLC shield for an additional 200 MAG. Other spells were Thundara, Fira and Aerora which is useful for farming monsters, but requires a modification for some of the tougher bosses. Other schemata used for staggering (like Equilibrium+) also work well.

Soldier of Fortune: This one turns Heavy Slash into Artemis Arrow, an extremely powerful attack. Equip a weapon with high strength. Equip a shield with ATB Speed. Use either the STR or the ATB speed accessory which allows you to steal debuffs. I had Blizzara in one of the slots for staggering while my second schemata's ATB recharges. The last slot is situational. I found ATB Charge to be useful.

This setup allowed me to clear most of the tougher monsters with ease. Chocobo Eaters, Reavers, Cyclops, Zomoks, Zaltys and some others would die in 20 seconds. The only challenge were the Earth Eaters which I didn't bother with in the end. For Ereshkegal, Poison on the Magic/Stagger schemata is really convenient.

[Da_Cloud]

Never really bothered with the ultimate lair yet. I reached the dreadnought, but I never got passed that guy. And I wasn't really surprised by that, out off all the enemies I only ever had trouble with the dreadnought and earth eater. 

While farming those pesky soil seeds on the outskirts I'd already defeated some of easier big mobs like Cyclops, Reavers, ect. Especially the Reavers are worth defeating early as those drop one of the better weapons of the game

[Chaos]

I believe it's the Reaver Omega that dropped my 900 STR & MAG weapon. I also had some problems with the dreadnoughts. They were easy, but took a while to kill. I used 100% magic immunity against them since their physical attacks either miss you because you are out of range or are easy to block. I was never able to stagger them before they used Wrecking Ball, though. My fights against them basically consisted of casting random spells while waiting for Wrecking Ball. As soon as he begins casting it, I would spam Blizzara and stagger it. Once staggered, a few Artemis Arrows or Elementas should do the job.