I Become An NPC That Can Do Infinite Job Changes

When Su Mu woke up, he realized he had been transmigrated to a game and became the lowest-ranked NPC, a farmer. In a world of endless war, Su Mu would not be able to protect himself as a farmer.
However, he suddenly came to realize that he could change his job as many times as he wanted.
In his first job change, he became a Militia and gained the ability to fight.
In his second job change, he became an Archer and gained the ability to make long-ranged attacks.
In his third job change, he became a Lancer and gained the ability to pierce armors.
In his fourth job change, he became a Heavy-armored Knight and gained the ability to switch between defense and attack with ease.
In his fifth job change, he became a Holy Knight and gained the power of Holy magic.
Su Mu completed countless job changes and managed to gain infinite power.
When the game and the real world merged, Su Mu was already the renowned Dragon Rider that had conquered lands and built the strongest kingdom to have ever existed.