When you enter the Unstable Iso-8 Story Event, you will be prompted to select a Clearance Level. For this event, each S.H.I.E.L.D. Clearance Level (SCL) will also display the minimum and maximum level enemies you can expect to play against. For most missions, enemies from each mission will start at a specific level, and their level will increase at a fixed rate for each mission completion. Hard and Essential Missions will increase in difficulty a maximum of four times and all other Story event rules and rewards will still apply. Easy and Join Forces missions will not increase in difficulty after each completion.
SCL Levels, Rank Requirements, and Enemy Level Minimum/Maximums: