Maybe it will be more like Sengoku Basara OST?I dont think any of those staff are from Magi so comparing it to Magi is not really fair.
Sawano is an interesting choice for the series though I figure itll probably be one of his more toned down works as Seven Deadly Sins is simply not as epic as say Attack on Titan or even Aldnoah.Zero.
Which I wonder if we'll get another one of those SawanoHiroyuki[nZk]:xxxxxxx type of songs. Would be epic.