So in the anime demons are able to manipulate their flesh and bones to make demonic weapons.
Sadly most ds games don't use this feature of demons mostly because it's very easy to forget about and balancing issues, non the less having it still would be a cool feature to have in the upcoming game Hinokami
For a rundown on how to get it exactly on a specific level a special demon would be ability to teach you the flesh manipulation ability and give u a random demonic weapon the weapons in general would have effected such as : poison, bleeding, slowness, etc. after you learn the flesh manipulation ability you will loose 50% of you current level plus 25,0000 yen (or whatever the game currency is) the weapons would give a Small damage boost however u must have the bda that relates to the said weapons to get the boost.
The demon weapons would be:
( Former) Upper moon: 6 Gyutaro blood sickles
Upper moon 4: bone dagger and spear
Demon claws: probably in the anime
Arm blade: I'm a mk fan
Flesh katana: you won't keep your breathing
Long story, short having this would be a cool feature to have in game, fell free to send your feed back.