Yeah, pretty much he just hits things, but he has some variation on
how he hits things. Looking at his features now, there are a few things I've been completely neglecting:
Frenzy
While raging, you can choose to frenzy. You can make a single melee weapon attack as a bonus action on each of your turns after this one. When your rage ends, you suffer one level of exhaustion.
Mindless Rage
You can’t be charmed or frightened while raging.
(technically he shouldn't have been frightened yesterday.)
Intimidating Presence
You can frighten a creature that you can see within 30 ft. If it can see and hear you, it must succeed on a WIS saving throw (DC 13 or be frightened until the end of your next turn. You can use your action to extend the duration of this effect each turn, unless it moves out of line of sight or more than 60 ft. away from you.
Relentless Rage
If you drop to 0 hit points while you’re raging and don’t die, you can make a DC 10 CON saving throw. If you succeed, you drop to 1 hit point instead.
The DC increase by 5 each time you use this after the first, resetting to 10 after a short or long rest.
Retaliation
When you take damage from a creature that is within 5 feet of you, you can use your reaction to make a melee weapon attack against that creature.
He really is a powerhouse if played properly. In my defence, it's hard to play a PC to their full potential while managing everything else in a combat encounter.

I'm happy to keep on sending him in to hit things, but if anyone wants to shout up to give him specific instructions or reminders, please do.