So I'm pretty sure that the music that is playing during Sun and Blake's battle in V4 E3 is From Shadows Part 2. It's hard for me to hear the lyrics over the fight, but this is what I got.
Go where you need to
No, I won't leave you
I'll follow you for only all of time
Until you're pieced through
One thing I told you
An then the Sea Dragon Grimm they're facing shoots lightning and I can't hear anymore of the lyrics. I'm probably wrong about most of these lyrics so I was wondering if anybody else could hear them better.