It literally comes out of nowhere. Now you may say "but Titan has rock and everyone loves it." Heres the thing about Titan. Even before the match starts, theres a guitar rift and the theme gradually builds up. So when the rock does start playing its not entirely out of nowhere. His theme also fits with the fight itself, things falling and exploding, Titan trying to send you plummeting off the arena, its chaos and the rock adds to it.
Literally out of nowhere. Then comes Shiva. With a beautiful orchestrated theme that fits her character thats both elegant and gives a sense of her strength and then.... rock music. The song doesnt do her justice at all. It sounds too much like a montage song. I expect Shiva to make a montage of her working out to be a boxer or something. Now look at Garuda's theme. It fits her. It starts of with similar vibe as Shiva but it is done so much better and it starts soon so it doesnt feel like it was placed there as an afterthought. She also had a mix between a guitar and orchestra which is what shouldve been dont with Shiva. Also Garuda's theme is far more tragic as the lyrics fit her lore. Yes her theme has lyrics, its just hard to hear their short, but it gives a better sense of who she is. This is Garuda's lyrics Falling too far from the light, Deeper into the night, Lost here inside my own hell, I am a broken angel. Those few lines make Garuda far more interesting than any Primal in my opinion.