Choose a theme for the above poster.

Cathrion starts playing her favourite music:
https://www.youtube.com/watch?v=mVpfOQ1N3aM

All the Elven neighbourhood closing their ears from the noise that came from Cathrion's room. It was trash music in its purest form.... it exist just to annoy people.

The other Elves starting to yell at her, but Cathrion made her Troll face and didn't listen. She even increased the volume.

But then her sound system exploded because of the pure trash it had to emit.

Finally, victory for the Elven neigherhood:
https://www.youtube.com/watch?v=jdxwY_jQmCE

For now...
https://www.youtube.com/watch?v=0OBck4Ymlk0

Daha's inner monologue after he does something jerkish like stepping on a Troll's toes while wearing his plate boots, or slapping something out of an old ladies hands.
This would fit I think

https://www.youtube.com/watch?v=1eh2FtRGrqg
It doesn't fit for an silly Elf... but for the Death Knight:
https://www.youtube.com/watch?v=WZz9mvCcyPk
https://www.youtube.com/watch?v=_yWZBC0_bhQ

The menacing tone of the music, the wolf howls in the background and the drums give it a distinctly Orcish feel to it. To me, anyway.
This nimble elf is no stranger to stealth and infiltration. Some might even go as far as to call her a professional.
Those that are in the know, that is.
Having turned the grace and beauty of her people into a weapon, she proceeds with her mission. Nothing out of the ordinary.
But alas, something goes wrong. She is detected!

Her plans foiled, with guards closing in, doors slamming shut, she needs to find an unconventional way to get out of this unfortunate and precarious situation.

Cue theme!

https://www.youtube.com/watch?v=bnpg47YCMWg
https://www.youtube.com/watch?v=OQfjIw3mivc

sorry if I didn't hit the mark ;/
https://www.youtube.com/watch?v=bFSKZEgstCM sorry if it doesnt fit, as i sadly dont know -that- much about your characters, except the pro illidari theme.

if it was wrong, then mork is terrible sorry.
This one always makes me think of Orcish tribes :-)

https://www.youtube.com/watch?v=UwLtyvGdNbc
https://www.youtube.com/watch?v=QxJrjV4PNXA

I think this is perfect? Elegant and ..evil.
https://www.youtube.com/watch?v=dCnO2Gnzauw

Night elf mohawk ?
But nah here's something real :
https://www.youtube.com/watch?v=LuUhNozGvpY
https://www.youtube.com/watch?v=Cgi3qYEr3Bs

There's very little to work with here, so this might be slightly on the generic side of the spectrum. However, from what little I could gather from a look into your post history the character seems like a bit of a run-of-the-mill soldier type. And what'd be better such a concept than the human briefing music from Warcraft II?
Alright, so, Shodan ... first of all, mandatory "Frakenstein's Monster" song!

https://www.youtube.com/watch?v=SWFVi3jEJMY

But yes, overall I just imagine when she's not up to any particularly dastardly acts, back in her little hidey hole where she conducts all her various experiments, there would be a slightly mechanical, overly eerie and unrelenting kind of atmospheric soundtrack ever present in the background of wherever Shodan may be, like so ...

https://www.youtube.com/watch?v=pYzgQzFFhSc

When she reveals herself to a potentially suitable candidate for her special kinds of "enhancements", before any force or subduing occurs by while she states her intentions, this kind of music would be quite suitable for that particular kind of confrontation ...

https://www.youtube.com/watch?v=AH9rBVwYo1w

The sound track of said forced conversion ...

https://www.youtube.com/watch?v=oUhf3yNyXDA

And finally, in recognition of the fact Shodan is basically the Josef Mengele of Azeroth ...

https://www.youtube.com/watch?v=K6_zsJ8KPP0
https://www.youtube.com/watch?v=HWqKPWO5T4o

One day you will be like him.
Dakuh's constant inner monologue as he searches through the streets of somewhere like the Drag, looking for potential marks ...

https://www.youtube.com/watch?v=LNEs_N2iBhg

Dakuh's theme for when he spots a mark, and begins to follow them covertly ...

https://www.youtube.com/watch?v=r_r2t35zi5I

Dakuh's fight theme for when he can't one shot someone in the dark and a real scrap goes down ...

https://www.youtube.com/watch?v=A51_5i-L7do

Dakuh's theme for when he's in his hideout, counting the coins he's stolen ...

https://www.youtube.com/watch?v=2_JTzEppKy8

Dakuh's theme for when he's finally caught and receives his comeuppance for being a no good thug.

https://www.youtube.com/watch?v=SfBcNIpoUmA

I eagerly await down votes for giving multiple themes when the topic title said to only select one theme. <3
https://www.youtube.com/watch?v=9vGnzKki5aA
makes me think of him. an old experienced veteran who have spent years if not decades fighting against one enemy... the orcs!
his devotion to fighting for the alliance, unmatched!
There's a word I always mentally associate with Rumika, both IC and OOC, and that is as follows ...

https://www.youtube.com/watch?v=BKz2U4fvA4U

... yep, "Slither". It suits the concept of the character, reminds me of the way many a scaled creature moves, and you even use it in posts from time to time. The song itself I find blends the right amount of smooth rock along with a touch of sweetness ... and also, just a smidge of sleaze. The chorus also reminds me a pinch of the notion of being a Demon Hunter or someone who sports her mentality at least, which is that everyone carries sin and can be cleansed.

In keeping with that theme ...

https://www.youtube.com/watch?v=BKz2U4fvA4U

... yep, another one!

"Yeah, we're standing in this jungle,
Yeah, with serpents I have found."

A bit heavier, for the times where a more "no nonsense" approach of making a deal with the proverbial devil may be in order.
https://swans.bandcamp.com/track/song-for-a-warrior

Sorry, I couldn't really think of anything, so this is all I could come up with..
May have missed the mark here, but so far, based on your posts this seems to fit.

https://www.youtube.com/watch?v=ZWqBm28ZKeE
https://www.youtube.com/watch?v=nM__lPTWThU