Well, this is coming more from my experience with Tao than with Arakune, but...
Yeah, she can be dangerous. Her 5B is about as fast as your 5A and can lead to 3.6k damage (!), AND she has a good long-range ground poke (5C) that can lead to 4k+ (!!) on counter-hit, so be really careful whenever you're on the ground. She's very fast and if the Tao player can hit confirm things can get painful.
But, Tao doesn't have any good anti-air options. She's got her 6A, that move where she claws above her head twice, but that's weak and prorates heavily and I believe it loses to both your j.B and dives. So, definitely, even more than usual, try to stay in the air as much as possible.
Some popular Tao moves that are punishable:
- her 6B overhead, that little somersault, is extremely unsafe, especially on startup. Punish! It often comes after a string of blocked 2As, because it moves her forward a little to keep the pressure on.
- A lot of Tao players, if they whiff an attack or push you too far away, like to cancel into drive to leap through you and land on your other side and continue with either 5B or a throw attempt. If you see this coming, Tao's really unsafe when she lands from the drive, and you can punish.
- Tao's only strong way to approach from the air is j.C, and I am pretty sure Ara's 5C stuffs this, like Dime was saying. Sweet. Haven't tested extensively though...
Otherwise, just watch for random drives. A lot of Tao players like to go crazy with the drives and it can feel overwhelming but it's usually pretty unsafe for them.
Hope that helps!