Are there any Edges or something else that adds to Composure Tests? I know that anything increasing Charisma and/or Willpower will boost Composure, but I was wondering if there are any ways to directly boost this test.

From the top of my head the Bravery quality.

I would also be willing to negotiate a bonus based on knowledge skills that reflect previous experiences (ie: professional skill Military 4 (SpecOps +2)).

hyzmarcasm (5 to 15 BP)
Adds one dice per level taken to any composure checks connected to scenes of torture, extreme violence, sexual deviance or possible rituals of the Cult of Cthulhu.

Sorry, this was the first thing that came to my mind.

Well, Guts adds +2 dice to fear-based Composure checks (and the most common reason for them by my reckoning) so why does Hyzmarcasm add only one for the same cost?

Let's see here, twice the bonus for the same cost? Yes, please!

Hmmm...

Note that the Bonusses from Guts and Hyzmarcasm do stack, so if you want to max out your Composure DP, you'll most likely take both.
There's several houserules doubling the Hyzmarcasm bonusses, though.


OT : The drug Brass Balls renders you immune to fear.
However, its price is not mentioned in Arsenal.

Yeah, guts. I meant that one when I said bravery.

Meh, I had it in mind that Guts was 10BP. Hyzmarcasm also covers disgust though. But yes, +2/+4/+6 sounds reasonable.

The Mercenary Credo Code of Conduct Quality from Runner's Companion.