The cloak that goes over your head and back?
There are few armor pieces with a cloak and shoulder piece, not exactly like malgus wears but close, though I'm sorry to inform you that NONE OF THEM have a hood.
There is a legacy armour that you can get that is similar. You'd need to be a marauder though & have legacy 20.
You don't have to be a marauder for that legacy chest, juggs can use it to, you'll only loose some armor since that legacy chest is medium armor and juggs can use heavy