Nero was a warlock formerly in the employ of Keeper Arachne. He styles himself in long velvet robes with a high collar but is generally of a lanky composition. He has considerable skills in necromancy.
A favourite pastime of his is torture which he endeavours in indiscriminately.
He first met Sailor Mercury when she was imprisoned as a part in the frontline squad during the attack on Arachne's dungeon near the capital. He gleefully tortured multiple prisoners in her presence and therefore lost any sympathy Ami might have had for him. He fled the prison when Mercury succeeded in her escape attempt and was later found in his library after Arachne's banishment. Not eager to fight a reaper he fled once more only to find the soldiers that invaded the dungeon.
He escaped from the soldiers and re-entered Arachne's service. Arachne promoted him to Keeper and put him in control of two of the Dungeon Hearts on Avatar Island. After funding and heavily reinforcing him, Arachne ordered Nero to cast a spell that dragged all of Ami's minions to his main dungeon to face his forces in a climactic battle (Nero's Spell parts 1 & 2). In the battle, he suffered defeat and was banished when his dungeon heart was destroyed. Before he could recover, Ami's surviving forces assaulted and destroyed his second Dungeon Heart, banishing him permanently to the dark gods' realm.
- Animate skeleton
- Redirect spell
- Shapeshift (snake)
- Transfigure into animal (frog)
- Conjuration (exploding device)
- Insect Swarm body