=Hero attacks work kind of like Mass Effect's "hacking minigame" or all of Super Hexagon's gameplay. They are timed per turn.
A basic version of that would look like the shitty scribble up there.
At the center of the combat field there is the enemy's vulnerable core.
Everything on the field moves in a concentric grid around the center.
You control the hero's vulnerable core with keyboard (W/S for moving inwards and outwards to the center, A/D for rotating field by its axis in the center, relative to your core.
You control your weapon in a small radius around your core with your mouse. touching the enemy core with the weapon causes damage.
There are shields – blocks of different shapes and sizes, that float on radians around the center axis and are impassable to your core/weapon.
Attacks on you are the same shit, except your core and the enemy's switches places.
From that basic scheme, there's a lot of variety that can be introduced:
Shields that rotate around the axis, shields that bounce you back, shields that phase in and out, shields that move in and out from the axis, shields that cause damage, shields that can be damaged and destroyed.
Enemy core moving around freely in around the axis.
Enemy core with weapons of its own.
Enemy core that shoots you with projectiles danmaku style
Enemy core that spawns minions that track and attack you.
Several cores at once.
Different weapons you can use: for example, a weapon with a lot of inertia behind it, that only deals damage if it moves quickly – the faster it moves the harder it hits.
Projectile weapons.
All of the shit the enemy does, employed via spells/consumables/equipment.