Hundreds of pairs of eyes are watching, the way they always love to do. None of them are privy to the carnage. None of them ever are.
The beast perfectly maintains the illunsion - a noble magical contract-worker of some kind engaging in a fair and close battle of magic and fisticuffs - to all but its prey. To its prey (the human calls its kind 'monster-knights of the Shadow Empire', but a name is a useless and unfilling thing to have for dinner), the beast has revealed its true nature, its thousand teeth and hundred claws and no less than fifty eyes.
Its next meal goes slack, eyes wide as it realizes just how outclassed it is. The crowd cheers for the beast's pretend-hero, for the beats of a fight that was never there. Its target screams, trying to get the crowd to notice it as it feels true fear for the first time in its rapidly-dwindling life.
They will never hear it.
The beast is almost immediately upon it, wrapping it in an embrace of death, breaking through flesh to bone with its claws, stripping it away with its teeth, consuming, sucking out the intestines and chewing on the stomach and lungs and savoring the brain and twin hearts of the other monster, swallowing whole the skeleton, lapping up the few last bloody remains so thoroughly that no one will ever know. It is finished, and the beast simply sits and allows its prey to digest as the crowd continues to gasp and cheer for the show it is putting on for them.
And as the false hero cheerily vanishes with a glimmer, the beast skulks into a dark, dark alley, dragging its claws deep into the walls and leaving one final sign that it was there, as Elm wakes up, groggily, zer body covered in foreign substances ze would rather not question the nature of. Ze rubs zer eyes, blinks, and looks at the wall opposite zer, into which a message legible only to zer well-trained eyes is carved:
THEY ARE PARTICULARLY DELICIOUS THIS TIME OF YEAR, HUMAN. I GENUINELY FEEL BAD YOU HAVE YET TO INVEST IN CLAWS OF YOUR OWN.
Silly beast, Elm thinks to zerself. Ze pulls out an index card, writes a quippy response, and stores it away in zer jacket pocket - for the beast to discover next time ze must once more do battle as Giga Sparkle Shatter Star - and sets off the long, dark back way home for a nice, hot shower and hopefully a fresh set of jammies.