
StreamOfTheSky |

Most common 2 methods both come online at level 9:
1. Barb 8 / Oracle 1 - non-oracle levels count as 1/2 for oracle levels for curse benefits, so with Lame curse you'll be Oracle 5 effectively and get Fatigue immunity.
2. Bard 6 / Horizon Walker 3 - Desert terrain will give you fatigue AND exhaustion immunity. Compared to #1, this one preserves full BAB at the expense of a worthless feat, 6 worthless skill ranks, and two more levels of Barb progression lost. So #1 is the better option.
There is also a Bard spell, Invigorate (get potions) or some sort of plant/drug I can't recall the name of right now for short-term rage cycling ability.