[Leidolfr]

Spoiler:

The good news is that at the end I saw Cruz awakened their latent power. The bad is that his sister died before combat Cruz, because I would have liked to see it, but well, I am satisfied to see that Arclight killed.

It is not why Aruka changed his mind, because now he saves his brother rather than kill him.

Or is that I wanted to kill because they know that if cross wakes up his power, then it would be a great threat to the world and why his sister wanted it kill to avoid cross to discover their powers and thus "Save" the world of the serious threat posed by Cruz.