This Daisenryaku II - Campaign Version supplement offers Xak vs Cloud campaign game that you can command Xak characters or Major Cloud's modern weapons, adds new maps and units such as birds/robots, and edits weapon stats and graphics and converts the graphics to Graph Saurus/DD Club format.
Daisenryaku II - Campaign Version and several blank disks are additionally necessary.
"Customer" was likely named so by being mistaken with Customizer as something that customizes Daisenryaku II.