Some notes on the new Kobu Jutsu Tanya:
B1 2+4 into rekka can be backdashed but not whiff punished. This was tested using reptiles ex slide. You can also choose to continue the rekkas to catch some slower backdashes
B1 2+4 into ex Rekka can be backdashed and punished by Reptile's ex slide only. The timing is also very strict, and if you fail, you get full combo punished.
B1 2+4 into ex Rekka breaks all armored reversals that are 9 frames or slower. It trades with 8 frame armored reversals (still testing) and loses to 7 frame or faster armored reversals.
So Lao, Reptile, and Goro (2 hits on punch walk) can always armor through the gap.
I can't test anything with Goro until tomorrow, but with Tempest you can B1 2+4 cancelled into back teleport to bait an ex spin. From there you can punish with a perfect run cancel into f2, or EX Tonfa toss. Versus Buzzsaw/Hat Trick, you have to teleport forward to avoid ex Spin and you can't punish.
Against Reptile, you can also use b1 2+4 cancelled into teleport to bait an ex slide, although it doesn't appear that he is punishable. However, he can't convert into a full combo.
Please hold off on declarations on character deaths until we do more testing as a community.