Youth career Born in
Bissau, Guinea-Bissau, Marciano played for local MEPA Academy as a youth. His talent wouldn't go unnoticed as in 2019, he was offered to go to Portugal to play for
Gil Vicente and later on for
Leixões.
Almería On 22 January 2022, Marciano signed for
UD Almería B on an undisclosed fee with his contract expiring in 2024 and a release clause of 40 million euros. He made an impressive start to his B team career by scoring two goals against
CD Intergym Melilla within just three minutes of coming on as a substitute, with one goal in the 31st minute and the other in the 60th minute of the match. He maintained his prolific form and emerged as the top goalscorer for his team, despite starting only ten games in the season. He scored in five consecutive games. Marciano began the 2023 pre-season with
the first team, but suffered an injury which kept him out until September. He made his professional – and
La Liga – debut on 6 October 2023, replacing
Ibrahima Koné in a 3–0 away loss to
Athletic Bilbao. On 31 January 2024, Marciano renewed his contract with the
Rojiblancos until 2028 and was loaned to
Segunda División side
AD Alcorcón for the remainder of
the season. On 14 August, he moved to
Betis Deportivo Balompié in
Primera Federación also in a temporary deal. ==International career==