The most Tatsumi could do as far as Vamp-status is just being able to control Eric, which he might do to be granted access to places and have Eric make a fool of himself or cover things up for him more. IDK, will speak with Jenna and see if she has any better ideas.

Definitely can have some play with his food (and by that I mean injuries because watching people struggle is very entertaining), but hmmmmm... I hadn't thought of sexytimes.