The Superhero Database Classification number, or SHDB Class, is a number that represents the overall 'power' of a character. All traits of a character are used for calculating the Classification.
What it DOESN'T mean
This doesn't mean that a higher class would always beat a lower class character. But the bigger the difference in Class is, the more obvious it is who'll win in a fight.
How is this calculated
( INT^1.3 + (STR*0.5 )^2 + (SPE*0.5)^2 + DUR^1.6 + (POW + (SPS*SPL))^2 + COM^1.8 ) ^ TIER
Super Power Score and Level
Every Super Power has a score (SPS) that is used to calculate the Class. Each Super Power also has 3 levels (SPL). The level is set when connecting that Super Power to a character. The level determines the final score, of the Super Power, being used in the calculation.
There's nothing Dandy can do to defend himself from manhattan hand waves
Both Higher and Lower dimensions were proven to be conceivable possibilities within the story of Space Dandy, too, since there was an episode with e.g. a visitor from the 4th dimension, and in other episodes all characters were warped into a 2-D Universe, so yes, spaces in Space Dandy can be however higher or lower dimensional in actual stories, so they are clearly a conceivable possibility which the authors of the Anime took into consideration.
Therefore, High 1-B cosmology at least, plus Dandy has OmniLock beyond that, so he has 1-A at least. He could've become The Narrator (== Tier 0) himself.