I sort the Enemies, Sub Bosses and Bosses on a scale 1 to 6.

1. Beginner- Extremely easy, a regular good player will never be hit [Sea Dragon, Sea Serpent]
2. Very Easy- Real easy bosses. If youre hit its because your drunk or something [White Death, Naga,]
3. Easy
4. Normal
5. Hard
6. Very Hard- Takes as much as luck as skill to suceed with this type of bosses. [Poseidon]