Oak Sage

• Oak Sage max health bonus only applies to health, not health %. Meaning you want to use
  Perfect Ruby (+38 health) over
  Jah runes (+5% health) as the
  Oak Sage aura only applies to actual health.

• Only one of
  Oak Sage,
  Heart of Wolverine or
  Spirit of Barbs can be summoned by the same player at a time.

• Summoning another spirit will dispel any previously summoned.

• Knockback does not apply.

• Aura also applies to
  Oak Sage itself, as do other auras, buffs and debuffs.

• Aura does not apply to
  Raven,
  Poison Creeper,
  Carrion Vine
  Solar Creeper, or Returned.

• Aura level equals
  Oak Sage slvl when cast. Casting
  Battle Command before summoning results in slvl+1, then casting it on the spirit results in aura level = slvl+2.

• Only highest level aura will be applied to allies within radius of multiple Oak Sages.

• +(1-3)
  Oak Sage (Druid Only) can spawn on ilvl <37 Druid pelts.

Blizzard wrote:

Oak Sage

• Min Life and Max Life values are averaged to always be the same, accurate to the tooltip

• Physical Damage Resist in Normal Difficulty increased from 0% to 25%

• Physical Damage Resist in Nightmare Difficulty reduced from 100% to 25%

• Physical Damage Resist in Hell Difficulty increased from 0% to 25%