Niiice, dude!
First run? What strategy?
BTW: Does anybody know what garb this one is?
https://www.youtube.com/watch?v=vVcFfF4olAI
Left it for my New Game + run so I was pretty beefed up. Each Artemis's Arrow was dealing 300k+ to him when he was staggered.
The strategy is actually very simple. Just make sure you have Phoenix Downs and Ethers. Nothing else is needed but them.
To make staggering easier, equip the Chaos Bringer on something like a magic-focused garb and just spam magic, whilst using a tank garb to block/reduce damage from Aeronite's attacks.
Then it's a case of:
1. Spam magic until first stagger
2. Spam magic until second stagger
3. Spam magic until third stagger
4. Spam magic until fourth stagger
5. One the 4th stagger is applied, activate Overclock and spam Artemis's Arrow with the Soldier of Peace garb
Use Ether to replenish EP and keep activating it when it runs out so you can keep spamming the attack.
Block when attacks are coming from him, otherwise that's it. Very easy. No need to replenish health as if you die you can just use Phoenix Downs.
I found Ereshkigal more challenging because you can't use Artemis's Arrow on him and he used loads of status-inflicting shite.