Hey Tank Friends!
Beastmaster's been thrown around a lot, in a lot of different forms, usually being dismissed as a limited job. But we can for sure work with the concept to show how it might play without resorting to that.
We do know Beastmasters exist from the goings on in Bozja, namely with Lyon and Pagaga. Thus, we know that at least some variety of Beastmasters use a one-handed axe and a shield. It's possible to also include a Whip in the repertoire of the Beastmaster, since they have used those in other games.
A suggestion from another thread was to give them a chain for their off-hand, wrapping it around the wrist as a sort of makeshift shield, but would also allow it to be used as a whip, or even just to be a classic leather whip, and could be attached to their axe. It's an option, but I've been sticking with the axe and shield for this concept.
The general concept I have for Beastmaster's gameplay stems from them being a capable fighter in their own right, but adapting their fighting style to attack in tandem with their Beasts. Rather than being a pet job, the Beasts I've selected here function similar to how Reaper's Avatar attacks work, being a GCD that also commands their called Beast to perform an attack, but not persisting on the battlefield.
For reference, here's the Beastmaster's main weaponskills, with a couple abilities
These weaponskills are basic, meant to be used in between calling Beasts in, but they all change whenever the Beastmaster calls a Beast from their repertoire, changing form and function, and even combo actions.
Also, take the potencies with a grain of salt, I selected potencies mostly to give an idea of how it might feel, less to be actually balanced.