The sword I created, dubbed the Astroblade, combines traditional craftsmanship with cutting-edge technology. The blade is made of ultra-lightweight alloy, making it easy to wield in any environment. It is infused with a nanotech coating that allows the wielder to adjust the blade's sharpness and length, adapting it to various combat scenarios. Additionally, the hilt houses a small energy cell, enabling the sword to emit a powerful plasma arc capable of slicing through even the toughest materials in the universe.
You are a skilled blacksmith in a sci-fi universe, and you have been asked to create a custom sword with advanced technology for a renowned space explorer. Describe the unique features and capabilities of this futuristic weapon.