How to Deal with Crouching Opponents
You can use your auto combo finisher by pressing forward + heavy attack on the 3rd hit which modifies the hit into an overhead.
You cannot combo from that hit but it’ll force your opponent to think about if it’s wise to keep crouching.
(And forward + medium on the 3rd hit gives you a low-hitting finisher instead against standing block opponents).
And yes, simply grabbing also works.
Note: Raging Strike to open them up if they’re just down-backing; it costs you 1 BP but for them to counter it is 2 BP, so you come out on top and set them up for a huge combo next time.