User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-36663391-20181209201655/@comment-37165251-20181209205600

@FrankieX98 They are from the same Material, it is said so. The Malebranche, as also the Evil Pieces, are made out of the Cristals that are found in Agreas.

Since Ajuka were studying the technology that the old Maous left in Agreas it is highly likely that he used some of the technics in creating the Evil Pieces that were used to made the Malebranche