I am searching for a specific novel, but I remember very little about it.

The main character was an assassin who died and was reincarnated as a noble heir in another world. The original noble heir was a lazy scoundrel who died because he was poisoned in his sleep. The main character then proceed to take over the life of the noble heir, and impresses his new family with his skills.

In the other world there is magic, and depending on your strength the color of your magic changes. At one point, the MC cheats at a dice game by using his transparent magic power, while normally only very high level people have transparent magic power.

Another time, the MC went to a blacksmith, was disappointed by the lack of quality of the metal there, and hired people to make him his own 100-folded metal.

On the other hand, if you know another novel with a reincarnated young master, I'll take it.

Thank you all very much!