[@Carlsberg]

hmm...That's kind of tricky depending on the methods of someone taking his energy but I'm assuming the method that your character uses. In that case since it's skin to skin contact (like X-men's rogue) He's either going to have his skin shift into material she can't draw energy through or since his body will not detect any immediate danger from her until she touch him, she may be able to take some energy until his body comes up with an efficient way to escape her touch, which I'm thinking, phasing.