Tips for different units.
grunts: weak, but can be dangerous when they surround, attack speed is slow and can be countered with either shield or duel.
Defenders: lots of health and a little armor, same attack speed as grunt, but can take out huge chunks of health when they charge (you can not stop this attack, so get out of the way), if you are facing a wave that has lots of these guys and/or behemoths/Mikus/Pontius, use a heavy weapon.
Assassins: 3 or 4 hit attack that has nice damage, very fast and temporarily stun-locks you, assassins have lower health but are great at getting hits in, use duel to prevent hits or shields to reduce their damage. (lightning is also useful as it stops the attack of the afflicted except for charging defenders, Mikus, Behemoths, and Pontius)
Behemoths: these guys are slow but have huge health and 2 attacks that are easy to dodge (swing: just run past (front to back) and he will miss, Ground Pound: just keep your distance), behemoths are great for getting excitement up (with lightning), but are easy to defeat.
Mages: Their fireballs go past armor, and can be shot from a distance (blue ones home in on you), kill these guys as soon as possible, or else you will need to dodge their fireball and fight off a group of assassins at the same time)
Healers: all they do is heal a small amount, amounting to one or two hits from your weapon, kill these guys last.
~~~Darth Caedus