A 31 attacking a level 32 mob will deal 18.9% less damage and take 19.4% more damage. A 31 against level 33 enemies has a larger break down 29.8% damage dealt reduction 36.4% more damage you take Having said this I did the first stage of the raid as a 30 and almost got the second of it wasn't for glitches (2 sword bears at once, sword vanishing, 12 gatekeeper for first sword, sword fell of map,)