My murderers have some insane pain tolerance.

so in my novel, my murderers go through alot, one in particular gets a lamp and a sludge hammer in the face, smashed into a coffee table, clawed at, punched, kicked in the groin, knocked down the stairs and hit in the face with a sharp rock. but my victims, get knocked out in two hits... any one else has almost invincible murderers?

I haven't really tried to kill mine yet, but my MMC and FMC are going to have to find a way to keep him from jsut vanishing on them in the middle of a fight.

My FMC is pretty lucky being that she is imortal.... now. But she got pretty messed up before hand. My MMC who is mortal gets messed up alot. My MMC is a big sook though whereas my FMC was like so what I have an arrow in my back, barbed wire cuts across my stomach, a shattered ankle and three broken ribs I'm gunna keep running to try and save my brother anyway.

All of my characters seem to be taking quite a beating >.> I feel kind of bad for them, haha, like I need to add a foreward "I didn't mean for it to be like this, I swear!"

I haven't got people as my murders but they do appear to be invincible. I have decided on a way to kill them but in the situation my novel is set in people will have trouble killing them. But my MCs are very human and can get pretty messed up. At the moment they have been quite lucky but thats about to get a lot worse.

Hm...if it bothers you, make them more prone to human weakness. :) Study real-life murderers. Maybe that will give you ideas.

(To be fair, surviving a sledge hammer to the face would take Superman-like invulnerability. Maybe your murderer is...other-worldy? A demon, etc?)

There've been some studies that have shown that people suffering particular psychoses have their strength and stamina increase considerably. They no longer pay a rational amount of sense to pain/injury and continue fighting tooth and nail long after a normal person's body would give out. If it's getting excessive in your story, you may want to scale it back next month, during the editing process. But crazy people can take more than your average beating.

Just remember, if you're quite determined, as I'm guessing your murderers are, you can withstand pain, fear, and all sorts of awful things.

People on crack are violent and don't register pain or damage at all. They can and do fight like zombies but are also quick and strong. This is something you can use. Futuristic or unknown or magical drugs could make the effects even more pronounced. Cops dread having to take down a violent crackhead.

Behind every murderer there is a motive.
There will always be a will behind this motive.
... It all comes down to how strong their will is.

Have you ever seen a stray dog chase after a possible meal? It will do everything in its power to get what it wants [ultimately food], even if it kills them. People can be much the same way if put in a fight or flight situation, especially if they have some type of mental illness {as stated above}.

Desperation is a powerful thing. That's why mostly every villain you've ever seen has God-Like 'stand their ground' powers. That's why the bad guy is hard to defeat.
Not only would it subsequently end all conflict, thus creating no plausible reason for the story to go on, but it would also just seem strange if the villain wasn't pressing forward with all their strength to win. ^^

I always forget to make my victims attack him ;-; so I guess he'd be invincible at this point,
but he's a determined person so even if he got full on attacked I doubt it would do much damage :/

My bad guys SO FAR have fallen pretty weak. Well, there are a lot of 'enemies'. One of them I'm going to make quite a bit harder than the others, but sometimes my bad guys don't last more than five chapters. xD While my main characters, on the other hand, have gotten beat up quite a lot but they're still alive O.o