How does the Frenzy Berserker Juggernaut rage/frenzy?

[sutasafaia]

Unless I'm missing something, you become immune to mind affecting powers, including morale bonuses. Rage is a morale bonus, so how would you still be able to get benefit from it? Not sure if Frenzy is considered morale also, but most of the builds I see mention frenzy/rage stacking. Wouldn't that not be possible without house ruling?

[Kelb_Panthera]

A creature can lower any special defenses it has if it wants to. I think the example given was an elf voluntarily dropping its sleep immunity.

[Necroticplague]

Unless I'm missing something, you become immune to mind affecting powers, including morale bonuses. Rage is a morale bonus, so how would you still be able to get benefit from it? Not sure if Frenzy is considered morale also, but most of the builds I see mention frenzy/rage stacking. Wouldn't that not be possible without house ruling?

Rage is not a morale bonus. It offers a morale bonus, which you wouldn't get, but you can still Rage and get the non-morale bonuses. So for a normal Barbarian immune to mind-effecting (and thus, morale boni) can Rage as normal, they just wouldn't get the bonus to Will saves (which is the only part that's a morale bonus, rest is untyped).

And on a similar note, no part of Frenzy is morale, it's entirely untyped boni.