After RED and BLU were shut down the mercenaries were unemployed for a while but hid out in various old MANN CO bases.
Eventually they joined the remnants of Shadow Company and ATLAS, which following the deaths of General Shepherd and Jonathan Irons had been led by two mysterious new benefactors.
Renamed Shadow Fortress, their power and prominence grows rapidly. Aside from the mercs, several former Overwatch operatives join along with a few criminals and vigilantes from Zaun.
Shadow Fortress also breed Plusle and Minun to be used as living shields, food, slave labour, test subjects and living batteries.
I will be posting more Shadow Fortress art soon, along with more info on this group.