If the Lycan's are in a deck for a BE, then you don't need darkness... That would cause them to not work with BE.
BE is the type of card that you don't need to use on lots of creatures; but you don't want to have only 1 in the deck if you rely on it. Therefore its best use is with creatures who are otherwise useful but for one of which you might use BE. It's a matter of good deckbuilding.
I'm still not seeing your point. This card wouldn't be good without BE. Heck, this card is kind of useless in an entropy mono. The only benefit this has over lycan is that it costs 1 less to play. Regardless if you're taking Lycans or Cat's for BE, you're going to be left with useless extras. As stated before, this just costs one less. If you go duo, you wouldn't be left with useless cards, since you could use them as stronger creatures.
Anyway, I'm expecting to see more death effect cards relatively soon, if not with this card, then hopefully the next update.