Acquiring Fear as a trait (Deathwatch)

The last thread I posted brought up another thing I've been wanting to get to grips with. How can a Marine gain the fear trait without being lucky and getting it as an armour history? Should it be a Deed or something like that? What kind of things need to be accomplished to achieve it?

Ideas in any number of combinations

perhaps facing X number of elites enemies in single combat
incurring a certain amount of collateral damage
Treating mortal allies as expendable on a certain number of occasions
Have a particularly horrifying appearance/disfiguration
Intimidation +10/+20
Str 50
For an xp cost I was at least thinking 1000xp

Other ideas?

I'd support the idea of having it be a deed OR a Chapter specific talent that is given to Chapters that operate on using Fear.

But in regards to the suggestions, I don't think that collateral damage or use of allies would make your enemies fear you. More like it would be the result of kicking ass and making great displays of it so that the word spreads among the enemy.

Elite advance with intimidate +10 as a prereq?

Hmmmm, that seems a little easy

How about
1000xp
Elite advance
Intimidate +20
Str 50

I think the Str should be in there since it could account for physical presence. And, Intimidation should be maxed out just because.
And then to get Fear (2) you have to be rank 6

What do you reckon? Also, did you like the final idea we came up with on the Command Through Strength talent?