Considering there are more than one of them running around already, I'd say it's a strong theory.

[But he'll lean forward to look at this whack diagram... The fuck is happening here.]

—So you think they're two conflicting entities, then? Working together in a sense, but not really a cohesive unit. [Tap tapping at his chin.] ...Well, if we're talking curses, they can serve a number of purposes but they generally lead to things like death, loss of spiritual consciousness, that sort. I've dealt with targeted curse marks before - typically whatever creature it belongs to uses it as a compass to find you later. To, you know- [Waves a hand!!] -kill you horrifically or siphon your soul from your body, whatever it is that it happens to do. Could indeed be something like that in this case, if it's not a type of slow possession or kill-by-contact kind of thing.