From Valladolid, Mongil was part of local club Real Valladolid’s academy during his formative years. He graduated to the Real Valladolid reserve team and in the 2011-12 season made his debut in La Liga 2 with the senior team. He then switched over to Atlético Madrid B and played in the then third tier Segunda División B.
After a few more years in the Segunda División B with a few other clubs, Mongil moved to Georgian club FC Dinamo Tbilisi in 2019. He played in the UEFA Europa League qualifiers with them and then moved briefly to ATK in the January 2020 transfer window. Víctor with nine appearances in the 2019-20 ISL won the ISL Championship with the club.
Once the season ended, he re-joined Tbilisi and now joins Odisha FC on a free transfer. During his time in Georgia, he won the Erovnuli Liga (Georgian top-tier) twice in 2018-19 and 2019-20.
The 29-year-old centre back who can also fill in at right back has made over a 150 appearances in Spanish league football and 59 appearances in the Georgian top tier.