Practice more necromancy

You think for a moment and then think to the zombies 'surround Mike'. Immediatly they begin shambling towards the real little boy who quivers in fear as they surrounded him. "Um Sam," he squeaks "Could you stop them?"

"But I told them to. They're not going to hurt you," you say. Still the fact that you have absolute power over these things is pretty amazing. You have another idea and focus on ten of the zombies, using dark energy to remove their flesh from their skeletons. You raise your hand and purple-black energy engulfs ten of the zombies. When it fades they're no longer zombies, but skeletons. Animated skeletons that stand with more intelligence in their eyes than the zombies, and more ferocity. They don't look propped up anymore, they look like proper soldiers.

"Skeletons now!?" Mike cried.

"Yeah, and I'll have to arm them somehow," you murmur. Another ability from the amulet suddenly makes itself known and you gesture with your fingers a little over the skeletons. Shadows form around them and shape into swords and shields, the shadows then fade and these items lighten into steel, though with a black-purple tint to them. You might as well have forgotten about your child form as you created a hovering throne from shadows and garb yourself in a cloak of darkness.

Rather abruptly you remember how foolish it looks on someone as little as you currently are and so you return to your teenaged form, though taller and with significantly more muscle. However your skin is also paler and your hair's pitch black, while your irises are now red. "I'm the Master of Shadows," you declare to Mike "With this amulet I'll become a truly mighty ruler, don't you think?"

Mike gapes for a moment, and then bolts. You shrug and turn to face the city, twinkling in the distance. You weren't ready for an attack yet though, no not yet. There was still so much to the amulet you had to unlock.