Agnofinis, Terreofinis, and Mortfinis
These are evil spirits that have manifested inside the skeletal remains of Iron Maiden victims. They are all generally slow and lack intelligence, making for a rather easy fight. Most of these will be wielding hatchets or swords; a few wield a pair of bladed shields that they throw at you in a repetitious pattern that amounts to little more than an annoyance. If the finis get close enough, they can suck Dante into them, in which case they will spin into the air and smack back to the ground, destroying themselves and injuring the player. The finis are too common to amount any special strategy to them, kill them using whatever method you like.

 Puiar
The Puiar are evil spirits manifested to a form similar to that of a vulture. Their attacks generally come from the air and include an energy volley and a claw swipe. Again, they are weak and too common to amount any special strategy. Use whatever method you like, guns are preferable.
(Author's Note: I personally enjoyed skeet-shooting with the shotgun... "Pull!")

Msira, Homromsira, Ghusmsira, and Jomothumsira
The "sira" class enemy is more of an annoyance than it will ever be a threat. Attacks include claw swipe, fire punch and poison spray. They attack in groups, so use them to perfect the Twosome Time ability. Otherwise, use whatever method you deem necessary.

Pyromancer, Auromancer, and Brontomancer
The "mancer" class demon is a possible threat to Dante if he's careless. They utilize demonic magic to fire elemental attacks at him. Keep clear of them and attack from long range so their attacks can be avoided. If forced into close confrontation, quickly combine sword swipes with Twosome Time to keep them at bay.

Flambat
These small fire demons are yet another annoyance in DMC2 (Author's Note: There seem to be a lot of annoyances when it comes to the enemies, I detect a pattern here...) The Flambat flutters around Dante and attempts to burn him, a quick shot from your preferred firearm will dispose of these in droves.

Demonchorus
Demon spirits manifest in the form of bugs to form these creatures. They begin to glow yellow before causing a fireburst at Dante's feet, dodge quickly and return fire with your preferred firearm.

Spicer
The landmines of the underworld, these spheres explode when approached or shot. Keep back and take them out with a well-aimed bullet.

Infestant
The Infestants on their own aren't much of a threat; quick sword slashes dispose of them easily. Their main ability is to take control of human machines of war. Dante confronts an Infested Tank and an Infested Apache during his trip through the city.

Erupt Cells
Jellyfish-like demons that multiply when attacked. Stay out of range of their stunning attack and eliminate them with the bow gun.

Blades
These are similar to the demon of the same name in DMC1. Stay clear of their claws and use the bow gun or sword swipes to eliminate them.