Max accepted Iris's offer and became an official member of 'Shadow Wolves', a weird turn of events but it was needed as he could use all the different missions and experiences to gain levels and assassination points, as his divination said: "There is no limit to how strong you can become, as there shall always be someone who can fight you on equal grounds."
If he wanted to fight his classmates, the demon king and his generals, or even the celestial beasts and other mystical beings of this world, he would need to get stronger, much more than he currently was.
He had gone from "guard" to "high-tier member" in a matter of days, meaning he would need to take on the hardest of missions.
He would obviously be paid, each task giving him around 5000G, which baffled the boy when Iris told him.