LazySageDao
maybe all of plane have multiverse but door to Higher Dimension is closed or Even is destroyed. Edward Being Not prime but become prime because of merlin also make sense if you remember merlin one time say edward following legacy of arcane emperor in eariler chapter mayve arcane emperor was Prime Edward who reincarnated in Magus Era
world have multiverse but individuals cant achive 11 tier becouse know one plow the path to higher dimentions. like their is a door it is open but on the other side their is a gipsy plate that block the path so otheirs dont know what their is so they are afread to make first move. but in cosmic plane magus race pave the path and made it in to maglev line and not winding path thru the forest