So i am wondering what is the difference between those two ?
Is one continuation of one another ?

Hello.
No, they are not the same.MotBW is based on a campaign that you slowly conquer shard,meet and chat with other masters.
Of course the main plate of the game is the same more or less.There are differences like the increased combat map size and no similar campaign in Imperium but it is based on the same formula.
They are based on the same engine so.....crashes,errors and bugs are more or less the same.