What Rage activates

Rage enables the subclass's main combat loop: the spiked-armor bonus attack, Battlerager Charge, Reckless Abandon when you combine Rage with Reckless Attack, and Spiked Retribution at high level.

What remains useful outside Rage

Outside Rage, you still have ordinary Barbarian attacks, grappling, and the physical benefits of your equipment, but most of the path's distinctive action economy and retaliation are unavailable.

The normal Rage restrictions still matter

Battlerager adds armor-based options to Rage, but it does not turn Rage into a spell-friendly state. The normal 2014 limits on casting and concentration still apply, so a multiclass caster must choose between those spells and the Path's raging combat package.

Why Rage duration matters

Because several features shut off when Rage ends, losing Rage can collapse both your bonus-action offense and your mobility. The path gets much more value from committing Rage in encounters where you expect to remain in close contact.