This Avengers Age of Ultron: Ultron Prime V2 custom minifigure looks great and features custom made limbs and sculpted armour using Greenstuff.
His arms are made from arm ball sockets from a LEGO Skeleton minifigure and the elbow and lower arm sections are from a Minimate. His legs are from a LEGO Super Battle Droid legs chopped up and glued together with LEGO lever piece balls and skeleton arm sockets.
The minifigure has then been nicely painted with black outlines and drybrushed with silver to give it a metallic look.
Overall a great minifigure – well done!