Here is the full list of all 19 Renegade Grounds: Episode 2 achievements.
Completed Prison Cell Block and Upper Prison stages.
Completed City Centre and Church Tower stages.
Completed Dirt Fields, Army Camp, and Coalburn Factory stages.
Completed Ironwood Village, Desert Cliffs, and Kiverhim Holy Temple stages.
Completed Waterside Workshop and Mount Dismal stages.
Found a secret room in the Upper Prison.
Found a secret room in the Church Tower.
Found a secret room in Coalburn Factory.
Found and touched all 3 obelisks in the Desert Cliffs.
Beat the first 10 arena battles.
Beat the arena on Standard rules setting.
Beat the arena on Infallible rules setting.
Beat the arena on Marathon rules setting.
Beat the arena with the help of Ogoz the 3rd.
Beat the arena with the help of Tororm.
Beat the arena with the help of Iron Assistant.
Felled Garopontis in the arena.
Felled Avaj Python in the arena.
Felled Klamu Matriarch in the arena.