grueling (adjective)

1. The protagonist went through a grueling journey to overcome his fears and save the world from destruction.

2. In the comic series, the superhero faces a grueling battle against a powerful villain to protect the city.

3. The fasting during Ramadan can be a grueling experience, but it is a time of spiritual reflection and devotion for Muslims.

4. Why did the scarecrow win an award? Because he was outstanding in his grueling field!