Like the title says, he can customize practically anything. That includes items, building, the terrain(!!) and more. If he is a morally good person he might use this to increase the living standards in the world and decrease inequality. Or if he's a selfish bastard he could use his powers to become a tyrant and live in luxury while feeding on the unhappiness of his people. But no, he chooses neither of these, and opts for the "I'll just do whatever and see where the wind takes me, I guess I'll use my powers to enhance the equipment of my friends lol."
Conclusion: MC's powers are very cool but he barely uses them, and it is very unsatisfying
