Fear Incarnate: "After an enemy at range 1-5 suffers a morale test, it suffers damage equal to the number of morale symbols on the chosen card."
Steadfast [X]: "While a unit with this keyword is suffering a morale test, the cards of the type specified by X are treated as having one additional morale icon."
I just noticed this interaction tonight and got really excited! I don't think it will ever make much of a difference in the game, but it's worth pointing out. Say, for example, Ravos the Everhungry is attacking Ardus Ix'Erebus. Ardus has a panic token on him from a Spined Thresher and Ravos rolls a morale result on his red die along with the modifier of two morale icons. The Uthuk player draws spends the panic token to cause a severity-4 morale test. The Uthuk player draws and chooses to resolve Flee in Terror, a Fear-type morale card with 3 morale icons. Because Ardus Ix'Erebus is Steadfast [Fear], Flee in Terror is treated as having 4 morale icons. After Ardus suffers the effects of this morale card, he suffers four damage from Fear Incarnate which is enough to cause an additional wound to Ardus Ix'Erebus.
Pretty cool!