Oliver: (Thank you, Emperor!)
He was quick to give thanks because getting a new skill really gave him a very pleasant feeling.
He even wanted to use the skill immediately, but then realized that now was not the right time.
There was no problem using it during the day. It was just that the skill was better used when it was really important.
Perhaps if he acted, he would be of great help to people.
However, it could be a bad thing because people wouldn't get the chance to level up as it could be that all the monster fish attacking the city right now were killed if he used that skill.
Worst of all, if the first group of monster fish that came was killed, there could be another group that was stronger.
By then, he would be exhausted while the people in the city were unable to fight them.
He needed to relax now, waiting for a really strong monster attack before using the skill.