Boris sees his type as IEI. The diagnostics based on the information given confirms this type. Introverted and ethical subtype for IEI means that the closest types (subtypes) are SEI and EII.
SUPERID energy is very strong and this is why it is unlikely for you to be any other type. Ethics is also very strong. SEI is the only other option which we could check in a future. Otherwise all information you have given confirms your type as IEI.