You are a famous 'Dragon hunter' you catch so many wild dragons and the Royal Family trust you

One day the King called you and he said "There's a blue dragon,he is destroying the other and our kingdoms.I want you to find him and kill him"

You agree and as you left the castle and travel you came across a huge castle you open the door

There's a huge blue dragon and there's a boy sitting in a thrown "Look's like there's a visitor in my castle." He said coldly to you