On 8 April 2018, Soni made his first team – and La Liga – debut, coming on as a late substitute for Portu in a 0–5 loss against Real Sociedad. On 31 August of the following year, after Girona's relegation, he was loaned to RCD Espanyol's reserves in the third division, for one year.[7]
On 27 August 2020, Soni agreed to a one-year loan deal with another reserve team, Villarreal CF B also in division three.[8] The following 2 February, he moved to fellow league team Celta de Vigo B, while still owned by Girona.[9]
On 16 June 2021, Soni signed a three-year deal with the Greek Superleague club Asteras Tripolis FC.[10] On 27 November 2021, Soni scored a brace and gave two assists, helping his club prevail over Atromitos FC 6–2 for Super League, making one of his best appearances with Milan Rastavac on its bench. He was voted man of the match for his performance.[11]
^[origin1904-p.cxm.fifa.com/tournaments/mens/worldcup/qatar2022/qualifiers/caf/match-center/400228711 "FIFA World Cup Qatar 2022™"]. How things stand in FIFA World Cup qualifying. 8 June 2021. Retrieved 26 March 2022. {{cite web}}: Check |url= value (help)
^Kévin Soni at Soccerway. Retrieved 20 February 2021.