Mysterious & Intriguing:
* The Shade
* Phantom
* Spectre
* Wraith
* Ethereal
* Void
Clever & Playful:
* The Blur
* The Echo
* Shifter
* Mistwalker
* Invisible Man (classic, but still effective)
Powerful & Threatening:
* Silentium
* Vanisher
* Null
* The Unseen
* Shadowstrike
Names with a Twist:
* The Visible (ironic, implying they can be seen when they choose)
* The Unnoticed (plays on their ability to go unnoticed)
* The Ghost in the Machine (suggests a technologically-based power)
* The Transparent (a simple, straightforward name)
Tips for Choosing:
* Consider your superhero's personality and powers: What kind of character is it? What are their strengths and weaknesses?
* Think about the tone of your story: Is it dark and serious, or lighthearted and playful?
* Test out different names: Say them out loud and see how they sound.
Ultimately, the best name for your invisible superhero is the one that feels right for the character and story you're telling. Good luck!