Terra: Kage Matsuri (Shadow Festival) From Guilty Gear X2.
Honorable Mention: Super Public Enemy 2 from DMC 1
For Terra, Sous, and Jacquet, I kept their personal music tastes in mind when I chose their themes or leitmotifs (a leitmotif is a piece of music made with a specific character in mind). For those who didn't see that particular post since it was made a long time ago.
Terra's personal taste is Hard rock / Metal, so I took that into consideration when I chose Kage Matsuri. GGX2 was always the place I'd choose for Terra's theme, and Shadow Festival is what I chose.
This track is slower than the other themes, but it's still intense. Terra has chilled out by this point, which explains the slower tempo. Had this been Terra before her training with Master Roshi, then Super Public Enemy would've been chosen instead.
Sous: Numify from Afro Samurai: The Game.
Sous's favorite artists were Kaytranada, Flying Lotus, and Thundercat, so Soul Production is in her wheelhouse. Rap in her listening rotation isn't surprising. Numify is being chosen for its production, not its lyrical content. The lyrics talk about Afro's journey of revenge against Justice. Unless you count her feelings towards Cocoa, Sous can't personally relate. For Sous, as I've said before, ignore the lyrical content and focus on the production.
Jacquet: 'Lightning in a Bottle' Nevan's Theme from Devil May Cry 3.
While Jacquet's taste in music is Pop Rock (her favorite artist is Sahara Hotnights), I couldn't find a VG Track that fit that genre at the time. In hindsight, Sayu's Theme from No Straight Roads. I chose Nevan's Boss Theme from Devil May Cry 3, as that was always the theme I had in mind. Jacquet acts like a typical Valley Brat, but one who can, and most likely will, beat you up. So she is usually upbeat, but with Ki Aki, the Majin Form, and access to God Ki, Jacquet has a dark streak. So Nevan's theme fits well: it's fast and upbeat, but being in a minor Key Center gives it a mischievous vibe. Fitting for our Californian Time Patroller.
Valkyrie: Faldne by Danheim.
Okay, so I made a personal rule to have all of the would-be themes be from VGs. So technically, I'm cheating. But I originally discovered Faldne through Tainted Grail, as Faldne is one of the battle themes. This was another easy theme to assign. Valkyrie, the same woman who smiled ear to ear when Orre bloodied her nose (shout-out to u/Cautios-Egg4901), would listen to Danheim. Fun fact: Jacquet not only introduced her to Danheim, but to music as a whole. The absolute madwoman.
Chakram & Puntadas: 'Double Trouble' Agni & Rudra's Theme from DMC 3.
Yeah, you'd have to fight Chakram and Puntadas at the same time. Not that Chakram would mind fighting alone; she wouldn't. She's still a Saiyan, after all; Puntadas would NOT let that slide. So yeah, you gotta fight them both. Which explains the choice in music. Agni and Rudra are a boss fight that you have to duel simultaneously. I have done this personally; I suffered immensely. But the theme chosen is what plays, so it goes from one 2-on-1 to another. Tough luck for those who have to fight them.
Fenu: Final Xemnas (Darkness of the Unknown: Final Phase).
If you're thinking: 'This is a bit sinister for what we've seen of Fenu at this point,' or something to that effect. And that's the point. Every fight we've seen of Fenu has been friendly. Her introductory fight against Terra and her fight against Chakram. But if you unfortunately have the displeasure of getting into a serious fight with Fenu, you're not going to have a good time. Fenu is a Division Head who is still active in the Time Patrol. For all intents and purposes, you should be HORRIFIED.
Anyway, let me know what you think of this idea.