Intimidate

Current PoE2 Intimidate is both offensive and defensive. The target takes 10% increased damage from all applicable damage and deals 10% reduced damage. It is not restricted to Attack damage. The incoming value joins other increased and reduced damage taken modifiers, so it should not be described as an unconditional 10% more damage multiplier.

The target takes 10% increased damage

Intimidate contributes 10% increased damage taken to the affected target's damage-taken calculation.

The target deals 10% reduced damage

The same debuff also applies 10% reduced damage dealt to the affected target.

It is not Attack-only in PoE2

The current keyword says damage taken and damage dealt without restricting either effect to Attacks, Hits, Spells, or a damage type.

Increased damage taken is additive with its group

The incoming 10% is combined with other increased and reduced damage taken modifiers at that calculation step. It is not independently multiplicative like a more damage taken modifier.

The source defines duration

Intimidate has no universal duration stated by the keyword. Blackheart applies it for 4 seconds, Wulfsbane for 8 seconds, and Presence effects last while their condition remains active.

Same-type Intimidate does not stack

Unless a source explicitly says otherwise, multiple Intimidate debuffs do not add together. The strongest applicable copy controls the effect.