You know what they say: an unprepared vampire is a dead vampire, so to make sure Dr. Jonathan E. Reid, late of both the British Army and this existence, doesn't become that vampire, we've put together a list of all the enemies you'll encounter in Dontnod's Vampyr. This doesn't include bosses though. We've got a separate guide for that, don't worry.
Guard of Priwen
Are you a rabble rouser? Do you shoot first and ask questions when whatever you shot at is dead? Do you believe in the supernatural, and also that the supernatural is evil? Then join the Priwen Guard, a bunch of humans who volunteer their time to patrol the streets of London in the middle of the night and who totally have loads of friends and wouldn't be a huge downer in a pub.
Because the Priwen Guard are humans it means they don't have any terrifying supernatural powers to worry about, although some of their units use fire or stunning attacks, and they're annoying because you'll almost never encounter one Priwen Guard alone.
Priwen Rookies are the scrub level members of the Priwen organisation, and are some of the easiest to dispatch. Rookies use melee weapons and generally won't bother you but can be extremely annoying in numbers. Getting rid of the Recruits in a group of Priwen early on is a good tactic, as one less enemy means one less enemy dealing damage, and they're quicker than the bigger, tank-style units and are thus harder to dodge around. Chances are that out of a big group of Priwen, the Recruits and Gunners swarming around will do more damage to you more quickly than the Priest or Brawler stomping about after you. The only resistance they have, though, is ranged, so you can also deal laughably huge damage with your vampiric shadow and blood combat powers.
I like to think a Cadet is a Rookie who's survived at least one night patrolling London. Cadets are about as squishy as Rookies, but are more experienced lads and are wielding guns or flaming torches, which can be a serious danger to the health of you, a very flammable vampire. Try to take them down as soon as you can to avoid building up that aggravated damage.
Gunners have essentially the same build and fragility as a Rookie or Cadet, except somebody has given them a firearm. Gunners fire off semi-auto bursts which deal high damage and can be hard to avoid. They do, however, stand still for the most part, which makes them particularly susceptible to a lot of your vampiric shadow and blood powers. In general, it's a good idea to take out the Gunners in a pack of Priwen first, because constantly getting shot doesn't do wonders for your health.
Brawlers are the tanks of the Priwen Guard. They're easily distinguishable because they're much burlier than the other units, and have a kind of shield strapped to one arm which allows them to block stun attacks. Brawlers are resistant to physical damage, particularly ranged, so if you're low on blood then save your special attacks for the Brawler. He has a pretty deadly shotgun and hits hard if you get close enough, plus will launch a charged attack at you for huge damage if it hits. A lot of his attacks deal aggravated damage. He is, and I believe this is a technical term, a bastard. Luckily he's also extremely slow and telegraphs his attacks very clearly, so it's easy enough to avoid him. Pick off the other units around him first so that you'll not get flanked while you're taking him on, and then just hammer away at him until he falls over.
Executioners have long distance crossbows and can snipe you with them from miles away, which is especially annoying if you're trying to beat a hasty retreat. They might also toss gas grenades if they're feeling frisky, which is quite often. Much like the Gunners and Rookies, though, they're pretty soft-skinned and will fall over quite quickly. Of more significance is that you can run into Executioners that deal damage types – for example the Fire Executioner can shoot burning quarrels at you. You can take Executioners down if you just run up to them and hit them with melee attacks repeatedly, because they have no melee resistance. They do not like that.
Chaplains are big lads who whack you around with a big cross on a stick. They can also use the big cross on a stick to stun you – that is, drain all your stamina if you get caught in its big glowy beam – and can deal aggravated fire damage on account of being very holy. Their attacks are very slow, but if you get caught in a combo of them they can deal a lot of damage. Chaplains are also resistant to supernatural abilities. I would therefore describe Chaplains, generously, as being a pain in the hole and have always most enjoyed dispatching them via the expedient method of repeatedly shooting them in the face. If you run out of bullets then dodge around them and keep hitting them on their blindside. Where's your god now, huh?
These are your supernatural enemies, mostly ordinary citizens who've been mutated into frenzied monsters by the flu epidemic. Do not feel bad about exterminating them. They are beyond help now. Ignore the subplot about Skals living in the sewers.
All the monsters, with the exception of the Ekon, can turn up as 'Ill-Formed' later in the game, which is like the regular version but with poisonous disease effects layered on top. Whenever you kill an Ill-Formed Skal or Beast their body will explode, so, like Sting warned us all those years ago, don't stand so close.
The Rogue Skal is your basic unit of Skal, so sort of the equivalent of the Rookie. They can't soak up a lot of damage, but Skals hit pretty darn hard – or, well, rip and tear hard with their monster claws and teeth. Their moves are more unpredictable than human foes, as they can leap at you to latch on and drink some blood, but a basic Skal's resistances are physical so they'll drop pretty quickly with some offensive blood or shadow attacks.
Like a Skal, but more angry, a bit tougher, and a bit harder-hitting again. Getting caught in a chained group of attacks from a Ferocious Skal can really do a lot of damage, and isn't best advised – not to mention that it's aggravated damage, so can really knock down your max health. Keep moving and gauge your distances well to avoid their lunges. Skals are quite easy to stun, but if they approach with their arms held up over their face it means they're blocking and your stun attack won't land. Use your vampire abilities to control their movement around you and make sure you don't get pushed up against a wall.
Dazzled Skals have high shadow resistance and will spit projectiles if you get far enough away from them (Ill-Formed Dazzled Skals throw up gross plague stuff at you in alarming amounts). Unlike other Skals their physical resistance is low, which means these bad boys go can get mown down by a determined doctor swinging a bone saw relatively quickly.
Blinker Skals are, I think, my most hated enemy in Vampyr. As the name indicates to those of us who love Dishonored, Blinkers can disappear in a cloud of smoke and reappear somewhere else, usually behind you. Some boss or higher level Blinkers will spawn an attacking shadow of themselves at the same time. Essentially, when you see a Blinker move, you move too, thus avoiding the attack that comes out of nowhere when they reappear. Ill-Formed Blinkers are even worse because they'll leave a cloud of toxic gas in the area that they disappeared from, which is lovely.
Stunning a Blinker can be difficult, as if you land the stun attack just as they blink then it doesn't count, and even when they're not blinking they move around a lot. Coagulation is a really good power to use against Blinkers, because it forces them to hold still for one damn second so you can actually hit them; Shadow Mist is less good because they'll probably not stay in range of it long enough to take any damage, making it a wasted use.
Beasts don't turn up often but there's at least one hanging around each district and sometimes the game will throw one at you in scripted fights to spice things up. Beasts basically look like werewolves but they seem to be another strand of the mutation. They swing slowly but move fast, and all their attacks deal aggravated damage. They chain swings together and then rest after finishing the attack, which means they're easy to dodge around and hit once they've tired themselves out. The key with these lads is to make sure you don't run out of stamina while you're standing next to them, because then you can't dodge away. Later in the game you can encounter Shadow or Ill-Formed Beasts, and depending on what choice you make some citizens might have unfortunate mutational mishaps too...
Ekon turn up later in the game, once you've reached the West End, and come in two basic flavours: Blood Ekon and Shadow Ekon. The title accurately describes both the powers that they'll use on you and the resistances they have (i.e. the Blood Ekon will chuck Bloodspears everywhere and resist blood damage). As a bonus, they flail a sword around because they are gentlemen and it hurts quite a lot when it hits. Ekon can be wiley lads to take down, because they have the same speed that you do – which means they'll also keep up with you if you decided to just run past them. Please let me introduce you to my old friend the shotgun as a ruthlessly efficient method of attack against Ekon. You can also drag an Ekon into a group of Priwen guard or vice versa so they all get distracted fighting each other, and you can skip merrily away into the darkness.