[@Scio]
	ya the lightning wouldn't be just [url=http://bokunoheroacademia.wikia.com/wiki/Electrification]electricity[/url], I did look at that quirk, while electricity is pretty much scattered, lightning would be more directed, so he could without the need of an outside equipment, shoot it out of one of his finger tips instead of only his whole body, granted it would still be attracted to metal more than any other material, so there would be ways to redirect his lightning.

[Hider=Draw backs]
Lightning draw backs could of course be the body numbing the more it's used, just like how shouto starts to literally get covered in frost when he uses his ice to much. The lost of motor function, lose short term memory, if there is a good deal of metal he will lose control any lightning that exits his body. 

Blood draw backs would probably be the most obvious while he may be less affected by having more blood than a normal person, after all it doesn't take a lot to nauseate someone, he would still become sluggish and nauseated if he uses to much of his blood, would a great deal of endurance to stand constantly causing wounds on themselves to release blood. Will emit not sure to much on some possible drawbacks, Blood lord/King doesn't say much of terms of possible restrictions besides just needing blood.
[/hider]

Of course got more ideas for quirks, though if I type all my ideas then it would just get overburden or more time than needed, guess most of the time I can think of more uses than the restrictions.