After failing to get playing time with BK Häcken's senior team, he joined AFC Eskilstuna on loan for the 2020 Superettan season.[3] He played 15 games in all competitions during that season.[4] In 2021, he joined GAIS on loan and represented the club in both Superettan and Svenska Cupen during the spring season.[4]
Slavia Prague
On 21 July 2021, Ousou joined Slavia Prague in the Czech First League.[1] On 3 October 2021, whilst playing in his first Prague derby, Ousou picked up a red card in a 1–0 loss against Sparta Prague; Sparta scored from the resulting free-kick after Ousou's sending off.[5]
Loan to BK Häcken
After failing to get regular playing time with Slavia's senior team, he joined BK Häcken on a half-year loan deal without option.[6]
Loan to Cádiz CF
On 1 February 2024, Ousou joined Cádiz on a half-year loan deal with option to make the transfer permanent.[7] A month later, on 9 March, he started his first La Liga match in a 2–0 win over Atlético Madrid, becoming the first Syrian to achieve this feat.[8]
Loan to Charleroi
On 31 July 2024, Ousou moved on a new loan to Charleroi in Belgium, with an option to buy.[9]
^"قائمة نسور قاسيون لنهائيات كأس آسيا – قطر 2023" [The list of the Qasioun Eagles for the Asian Cup finals – Qatar 2023]. Instagram (in Arabic). Syria Football Association. 31 December 2023. Retrieved 1 January 2024.