First of all, you should read the FAQ for the three sites (Anime, SF&F and Arqade).
After having done so, you may come to the conclusion that the question would only be welcome in one of them, in which case you have your answer.
However, you can come to the conclusion that it would be welcome in two/all of them. It's no surprise: there's bound to be some overlapping (especially between SF&F and Anime). So it comes down to 2 questions:
- Where do you think the question will help more people?
- Where do you think your question will get better answers?
I understand that some people may worry about the fact that Anime is still on beta, meaning there is a risk of losing good Q/A if we were to closed. However, I would like to point out that our stats have been growing steadily ever since we came out of private beta. Plus, our main focus there is (obviously) anime and manga, meaning that the community being built is 'specialized' in those fields. Having said that, it is my opinion that any question regarding anime/manga is a better fit for Anime. On that note, I encourage you to ask your Devil May Cry question over there.
Since this question in particular pertains to Devil May Cry, I'd also like to point out that we allow story-related questions about anime-style and anime-based games (see this post for more info). Mechanics and gameplay belong, of course, to Arqade.
Also, be careful with cross-site posting.
There are also some examples of (similar) questions that have been asked both here and at Anime:
From those you can draw some conclusions, and hopefully I've been helpful.
Let me me finish by saying, once again, that your anime questions are always welcome at Anime!
I forgot to say that we've been promoting an event called Flavor Day, on which we select a 'flavor' (or two) each week (on Saturdays) and encourage people to ask questions about it/them. Incidentally, this week's flavor (Saturday May 4th) is "games" and "sports". So questions about DMC will be a perfect fit there!