Just so you guys know, full moons don't happen every day. They're more of a once a month thing
You could make it so that you transform "normally" every day, and go into "crazy mode" once a month :turned:

Crap, nevermind. This universe has a bunch of moons that always shine fully :facepalm:

I agree that transformation to werewolf while carrying huge merit should also bear consequences. for instance a beast-like appearance that over time makes you more feral. perhaps causing friendly humanoids to be classified as enemies after a certain stage is reached. or perhaps certain quest-lines that open up while you have Lycanthropy and even afterward as part of atoning for your bestial rampages. also perhaps your affliction causes wolves friendly to you but violent towards NPC's to be spawned near you at random intervals while you are transformed, or perhaps being hunted as the animal you have become.

In oblivion they never stop shining fully though

If werewolves do make it in, turning into one should have consequences. Killing spree like consequences

The problem with this is many ideas I've seen on the subject give players either too much control (kill people or receive a small stat hit that slowly adds up) or too little ("cutscene" of you automatically attacking nearby people)
The first option would let you just either do nothing, attack bandits, or attack guards. This doesn't really do anything because you don't lose anything. Shopkeepers won't be dead, questgivers and NPCs that you've built relationships with will never be in the line of fire, and all of your victims respawn. The second option makes you feel far too detached and gives you no "responsibility" for your actions, because you didn't do it.

My idea would be that when you transform, you will start losing health at a steady rate. Every person you kill reduces this by a little, and after you kill 5-10 people (depending on how bad your condition is) your health will stop draining. The catch is ALL NPCs look exactly alike, are all killable and all have the same (relatively crappy) stats. This will make being a werewolf play out like a lottery game where you have to "scratch out"(cwatididthar?) the least important people. Your vision will also be blurry and reddish and you won't be able to see very far, adding to the feeling that you just have to kill anything nearby.

After you kill the number of people required, your vision will go back to normal and all NPC stats will go back to original levels (kinda like going out of "beast mode") but you will still be a Werewolf, letting you see the damage you did and giving you the rest of the night to do whatever you wanted.