Issue with Kitsune tails, mass, volume, and strength

So I have a story and it's a high tech (now +20-50 years) in which we have magical creatures. Humans explain magic (which is limited and exhausting) as being quantum physics (science shrugs it's shoulders.) One of the main characters is a kitsune, who after a failed gambit pile up decides to kill the man she holds responsible (who is oblivious to her ire.) I wanted to make this a very casual murder and had an image jump into my head... The victim laying down and the murderess sitting upright looking away from him, her tails flare up behind her and warp around the victim's head and suffocates him. The problem i have is I myself have a very tenuous willing suspension of disbelief and suddenly realized i had an issue... Shape shifter baggage. I've just been sort of dodging the entire shape shifting issue by not even mentioning it. Having nine tails would get in the way but one doesn't cut it for the scene. On top of this, despite being physically superior (short term, they suffer from a lack of endurance) I'm not sure if I would buy this scenario as a reader. Ideas that won't get me too out of whack with the high-tech feel?

If you're calling quantum physics 'magic', I'm not sure why you're angsting about this. If you're already saying that a still somewhat theoretical field of study can be harnessed by humans, I'm not sure I'd find it hard to believe that it can overcome a trope.

If you're explaining magic as quantum physics, remember that quantum physics allows for the breaking of conservation of mass and energy.

And hell, if you've got a high tech environment with a kitsune in it, I don't think 'shapeshifting works' is stretching belief all that much anyway.

What he said.

I don't think fox tails can do that. Wrap around stuff tight enough to smother a person, I mean.

I mean, I've never really seen a real fox close up. But from the way their tails are usually portrayed, they're not that flexible. I certainly couldn't imagine a dog or cat tail being capable of it.

Granted, this is a semi-malevolent nine-tailed shapeshifting demon-fox we're talking about. Normal rules of mammalian physiology may not apply here.

Fast Twitch Muscles can explain crippling strength but a lack of staying power.

Since you are using quantum physics as magic, you could say that magical creatures thereby also follow these rules for acts such as shape shifting. For example, the extra mass in the tails could come vacuum energy in space or quantum foam being converted. And if I thinking of quantum entanglement correctly, the energy could go to the users within a very short period of time.