no exceptions.
From one writer to another, beware of this phrase. It's exactly the mutability of your supposedly solid universe that will keep your readers guessing.
Not really.
If you write in an invisible pink unicorn to fix a seemingly insoluble problem, you'll lose a chunk of readership.
If you write in a clever way of using the rules and thinks the reader's already been told that the reader hasn't actually figured out yet, then you're ahead. But to make a twist like that work the rules have to be solidly established first.
I think you should look to Gail Z Martin's Necromancer Chronicles. I think you'd find a lot of inspiration for what you're looking for.
now what i need help with is that i am trying to find some ways for my character to use his powers over death to help people and not be to over powered. i have some ideas but i am always open for more.
one of the powers i thought up for him is that doing a little ceremony in which he places a drop of his blood (blood holds a lot of power) on the sensory receptors (eye, ears, nose, what have you) of a relatively fresh corpse he can experience their sensations within the last moments of life if the death was strong enough leave an lasting imprint. its informative but not a fun experience, plus its hard to get your hands on murder victims remains.
Interesting concept. I like!
Maybe your character can establish a link of communication with carrion eaters. Vultures, flesh beetles, worms, maggots, flies, etc. He might be able to commune with them (though I'm not sure how informative a conversation with a worm would be) or control them. The implications are disgusting, but maybe he could save somebody's gangrenous limb by compelling a horde of maggots to crawl in and eat out the dead flesh, but leave the living flesh untouched.
How about being able to concoct magical potions from certain molds or fungi that grow on dead bodies? Or from the petals of flowers left on tombstones for loved ones. The flowers themselves aren't anything special till they've been placed on the headstone; the act empowers or enriches them somehow.
Maybe he can take relatively fresh limbs and organs from dead bodies and transplant them into the living? If he can manipulate diseases, maybe he can remove the disease from a sick person and craft it into an immunization agent to administer to people? If he can manipulate dead tissue, perhaps he can preserve and craft dead flesh into garments (really nice fox pelt cloak) or disguises (wear the face/body of a dead person) or craft interesting weapons, shields, or armor from bone. Imagine a wicked looking suit of armor made from bones; the density of the bone has been increased dramatically, so that it rivals steel. Likewise he could make swords or shields. You could take that notion and run with it and have him craft some really interesting or useful devices from flesh or bone.
Of course there's always the novelty factor: So, Joe the Necromancer attends a boar roast and gets a little tipsy. He uses his control over dead flesh to reanimate the main course, and all a sudden this roasted boar jumps up and runs around the room, apple still stuffed in its mouth, causing hi jinks and more than a few fainting episodes.
Wouldn't it make more sense (and be more gross!) if, to see what the dead man saw, he had to put a drop of the dead man's blood on his own eyes? Just a thought.
I've always thought a nice twist on necromancy would be that the closer to "living" they are, the harder they are to affect. They still have too much life energy to them. So very old things are easier to animate (skeletons) than newly dead things. Everyone always goes the old=powerful route. It'd be nice to see someone go the other way.