Raiden is a cyborg. So you could make pockets in the armor somewhere and make them out to be interface ports or hide a slot in an inconspicious spot for a pocket. If you look closely enough, there's two layers of plating. If you were enterprising enough, you can hide a pocket behind the bigger plates on the front. Or, if you intend to make his sword scabbard, you can add slots to hold stuff in that, since it can attach to his back. Otherwise you can likely work pockets in on the hip or rear side, where pockets normally would go? My version of Raiden is gonna have slots built into the sword scabbard or hidden pockets built into the costume.
Don't meddle in the affairs of dragons, for they think you are crunchy and good with ketchup.
Current Cosplay Project:
Nero- Devil May Cry 4.
Current Costume status: Wig ordered.
Current Prop status:
Deathbringer: Full scale mock-up 85% complete. Design adjustments in progress.
Red Queen: Design in progress
Blue Rose: Not started yet.