It seemed everyone hadn't quite figured out the levels, so I listed them separately. Take a look if you want.
Star Beasts
Lord Level (War General Level), King Level (Planetary Level), Lower Emperor-Level (Stellar Level), Middle Emperor-Level (Universe Level), Upper Emperor-Level (Domain Lord Level), Top Emperor-Level (World Lord Level), Venerable Level (Immortal Level)
Darkness Breeds
Demon General (War General Level), Demon Lord (Planetary Level), Demon King (Stellar Level), Lower Demon Emperor Level (Universe Level), Middle Emperor-Level (Domain Lord Level), Upper Demon Emperor Level (World Lord Level), Demon Venerable (Immortal Level)
There are differences between the levels of Star Beasts and Darkness Breeds, so don't mix them up.
So it wasn't this author who got it wrong!
(Of course, if there was a mistake, it must have been because I wrote too fast and got mixed up, not because I was actually wrong →_→ Feel free to point it out!)
Of course, I'll try to standardize things later so it won't be so hard for everyone to read.
So the Star Beast side has one extra Top Emperor-Level, equivalent to a World Lord Level warrior. That way, the Star Beasts' Venerable Level can correspond to the Darkness Breeds' Demon Venerable.