was/Is satan the MOST Powerful Created Being of Them All?

No, Michael the Archangel is stronger.

Revelation 12:7-9.

 

Really it depends on one’s understanding of Ezek 28—if it is a double reference to Satan then he was an anointed cherub & was the wisest of all creation, if the passage is not about Satan, then a lot of our Satanology is speculative when it comes to his pre-fallen days. This is even true about his name possibly being Lucifer (which comes from Isa 14:12 being connected to Luke 10:18 & the Latin Vulgates translation of Isa 14:12). The problem with the name Lucifer is that in the Hebrew the term used in Isa 14 is helel & is not proper name (so many scholars disregard this ever being Satan’s angelic name, not to mention the fact that many deny that the passage is actually a reference to Satan). But as a professor once told me—all names have meaning—so it very well could have been his name even-- if it was not used as a proper name in this verse. Further many believe Rev 12 did not refer to his original rebellion, but to a later event after he had already fallen. In short, it all depends on how one interprets certain key passages. Regardless, the Bible affirms his reality even if it does not fill in a lot of the blanks with obvious answers!