Metal Gear Rising's bosses take over SCP – Containment Breach: Armstrong, Monsoon, Sam and Sundowner hunt you to their own themes.
Metal Gear Rising's bosses have breached Site-19.
You play SCP – Containment Breach as normal, but four METAL GEAR RISING: REVENGEANCE bosses have taken the SCPs' places, with their real models, textures and animations read from your own MGR install:
The bosses still behave like the SCPs they replace, so you survive and escape them the way you always would. Everything else, like zone ambience, items and the other SCPs, is the normal game. Single player.
What you need: SCP – Containment Breach (Steam, v1.3.12) and METAL GEAR RISING: REVENGEANCE (Steam), both installed. No files from either game come with this mod. The first time you press Play, it reads the bosses and their themes from your MGR folder, which takes about 15 seconds, and then opens the game. Later starts are instant.