normal - powerful compared to mortals, usually treated like peasants or slaves. used as guards for lower class typed demons. get fun out of scaring people. no weakness, but are pretty weak.
fire/elemental - the most common typed demon (mostly fire), able to use their element as their own. HIGHER CLASS elementals can control their element with more added bonuses or moves. weakness would be the opposite element.
shadow - use the shadows to move, can teleport and are generally hard to battle if against a mortal. scared of light sources and fire.
aura - uncommon, are usually higher classed in hell, can use their aura in battle or for terrain and scaling use. weakness would be other aura demons or seize demons who attack mentally.
blood - uncommon, are usually higher guards. very good at battle, can take large hits but are bad at defence. water would be weakness, as most cant swim.
seize - demons that possess people. are usually common in large households or groups, but are hard to figure out. two groups - full possession and mental attacking. weakness is physical attacks on the actual body and silver.
immortal - very rare, usually higher class. two forms - one cannot be killed unless the other is killed, but the other is usually a giant. weakness is the form that can be killed and full seize demons, though this is unconfirmed.
higher - Almost always a subtype of demon. Is the same as the subtype except much more powerful and with is less effected against weaknesses unless its overpowering. usually higher-classed in hell.
giant - usually paired with immortal demon souls, but sometimes can be seen roaming around. used as guards for very important demons or for the gates.
hellhounds - species of hell, similar to demons but are usually made up of bones. skull is usually showing and there are no normal types of hellhound. most are fire elemental.
Reference to this if you want, they aren't just for me and my friends characters c: