As one might guess. As a R4, Raya could easily use an AOE spell which could cover the whole space. It was just fifty kilometres after all.
However, such attacks cost quite a lot of mana and weren't too effective on opponents with strong defence. The reason for this was simple, when energy is spread, it will obviously not be as effective as when it's compressed, especially on hard targets.
For that reason, Raya used a minor AOE attack. It covered a significant length of space and was also small enough to be really strong if it landed. Especially under the buff of her DA.
Unfortunately, the sandworm was out of range. Which made the attack useless.
Raya felt that she might have to unleash her domain if she wanted to locate the beast. Even if it won't be able to do any significant damage, it should be enough to expose the sandworm at least.
