Ah. I see it now. It's the spiked choker. Ok. Thank you. Though why an equipment though? Instead of just a battle option? Also seems like they only physical attack. I understand why. Trying to account for the skills would be mentally draining. Probably. I don't actually know. I'm not a game maker. Poor mira gets the short end of the stick though. She's really not a physical attacker. Does the barracks battles also get an auto battle too? I think that would be cool to watch.
Using equipment for the trigger allows the players to have only some of the party members in the auto-battle mode, in case they want to have some control, apart from other small benefits.
Allowing the characters to use skills in the auto-battle caused some problems, where players didn't want some skills to be used. Since you're probably much stronger than the enemies already when you want to use auto-battles, just physical attacks seemed like the better solution to avoid that problem. Of course, you should have characters with strong basic attacks in the team in that situation.
The vanguard story battles can be "skipped" by "leaving the battle to your army", which results in a dice throw and text based resolution of the conflict. Coding an entire AI-system for your forces, just to make the automatic battles be visible, would be a bit too much work to be worth it.