Daywalker

[Bunnicula]

Vigor of the Night: At night or under complete darkness, you gain +2 to saves.

hmm. How about:
Vampiric senses: Under complete darkness OR if you have killed a creature within 24 hours, you gain +2 to all perception checks.

 

[Minigiant]

I added Slow disease and renamed it. Should be mostly done.

 

[tombowings]

You might what to have the bonus to the attack for blood drain work the same way as dragon breath does, increasing with level (+2 in heroic, +4 in paragon, and +6 in epic). This is keep it balanced at all levels.