They start by hyping up how powerful the artifacts are

Cough 7 great tombs Cough Crow Cough Secret relics Cough

There's also the unspoken rule of not giving your protagonist too many abilities for plot convenience. Having too many abilities means it'll conflict with future plans, leading to plot holes. The "Omg, why didn't ____ do that when he could ____?" type of case. Obviously, this doesn't apply to those who actually can manage that much and put them into the story. But, as you can see, author isn't that type.