I really like the story, my only problem are 11 and 12 year olds acting as a couple, in the 90's, in the wizarding society, without internet and other nonsense.
I didn't finish Age of Adepts, I only read it halfway through I think. But I think it's very similar to Warlock in The Magus World, it just doesn't have the crazy dream of the World of Dreams and Green is not a Psychopath.
Instead of the bloodline of Meliodas, it was better not to just ask for the Power of Darkness.
The only thing about Meliodas' lineage is being a dwarf and a little power.