# sea of glass

Possible meanings are 1) a sea is spoken of as if it were glass. Alternate translation: "a sea that was as smooth as glass" or 2) glass if spoken of as if it were a sea. 

# who had been victorious over the beast and his image

"who had been victorious over the beast and his image by not worshiping them" 

# over the number representing his name

"over the number representing his name by not being marked with that number"