I agree with you, she seems more suitable for Nightmare than Oni at a first glance.
Adding to the considerations mentioned so far, the auras are huge due to that 50mm base and sz 4, if you have anything that places it is going to trigger them.
However, I think we are focusing just on the front part of the card, which is great. But the backside seem more than decent to me:
The Rows of Teeth attack has a decent dmg track 2/3/6, that 6 being more meaningful due to the Puncture trigger. And it also has 2 more remarkable triggers:
- Execute: this trigger is rare, only Asami and Misaki have it in TT. And doubling it, could be impactful.
- Hole in the world: It is a nice reposition tool.
Tortorous Trance is made for Nightmare, I don't think you will use it in TT unless you got nothing else to do.
The bonus attack Coil Around Prey is, again, a great reposition tool. With both the push and the Glimpse of the Void triggers.
As for the consume, well, it sems cirumstantial to me, maybe in keyword you can From Two Worlds a low health 2 flickr tokens oni with From Beyond to draw a card and heal.
All in all, with Df 6 and Terryfing 12, Sz4 and 50mm, nice auras and great triggers it could work great being in the middle of the table with some support.
The big weak point that comes to mind is being an enforcer, which reduces her survivavility and her ability to get the triggers when wanted.
Pd: I am pretty excited to see the Sz 4 miniature of this insect-lady.