Eventually learning the circumstances of his father's demise, young Helmut Zemo blamed Captain America and decided to follow in his father's footsteps and avenge him. Zemo recreated many of his father's devices and formulae, including Adhesive X. Calling himself the Phoenix, Zemo captured Captain America and his then-partner the Falcon and chained them above a boiling cauldron of Adhesive X. Escaping, Captain America grappled with the young Zemo and accidentally caused him to topple into the vat of liquid. Captain America left, believing Zemo dead.

Helmut Zemo had, in fact, escaped through a secret pipe at the bottom of the cauldron. The passage through the boiling liquid left its mark, however, and Zemo's face was severely scarred. Zemo kept out of sight for a period of time, building a retreat for himself in Mexico, recreating more of his father's inventions, and plotting revenge against Captain America. Allying himself with Primus, the shape changing mutate created by geneticist Arnim Zola. Zemo finally launched his first major campaign against Captain America, using Captain America's childhood friend Arnold Roth as his pawn. Captain America managed to escape, however.

Zemo's second attack on Captain America was launched under the auspice of the Nazi mastermind, the Red Skull, and his daughter, Mother Superior. After Zemo underwent tutelage at the side of Mother Superior, the Skull provided Zemo with the opportunity to defeat Captain America by making him relive his greatest tragedy, the death of his young ally Bucky (a death that occurred due to the machinations of Zemo's father). Captain America managed to survive the ordeal. Later, hostilities erupted between Zemo and Mother Superior over who would become the Red Skulls heir. Zemo lost the fight, falling prey to Mother Superior's mental blasts.

Recently Zemo took the name Citizen V and put to gether a rag tag team of super villans to pose as a superhero team. They call themselves the Thunderbolts.