If you spend two black mana you get a single target removal spell at sorcery speed, which isnt great, but it isnt bad either
For my money, the best place to put The Moon Howling at Three Wolves is very clearly Liesa, Forgotten Archangel decks, as it upgrades the destroy to an exile, and you can choose to return Liesa to the field while your other creatures make their way back to your hand
As YouTuber In Third Person explains, Serena provides so much utility, a player can discard three cards, pick five cards from their deck, and force their opponents to activate their V cards with just this one card
Each has a normal version which you'll use maybe 10% of the time
If you attempt to field those characters with the ability equipped but the necessary weapon(s) missing, the game will let you know this