When knocked down by Sub-Zero, your opponent must defend against his overhead and low mixups. However, these mixups can be avoided using Delayed Getup or Roll Escape, which can leave Sub-Zero very punishable on whiff.
If you think that your opponent will use a Delayed Getup or Roll Escape, you can then set up Sub-Zero’s Arctic Trap. This is done by ending combos with B321 and walking backwards.
If your opponent does a Roll Escape, they will be frozen. Depending on the character, this is also safe against Getup Attacks.
Once the Arctic Trap is set up, Sub-Zero can then apply his overhead and low mixups. This is especially useful as it allows Sub-Zero to combo off of his overhead.
If positioned correctly, your opponent cannot counterattack Sub-Zero.
Because of this, Sub-Zero can attack again after a blocked mixup. This means that Sub-Zero can apply his overhead and low mixup multiple times in a row.
These mixups aren’t guaranteed though as there are a few ways to avoid Sub-Zero’s mixup. For example, if your opponent jumps at the right time, then they will avoid both the overhead and low.
Moves that go through the Arctic Trap are very viable options for stopping the mixup. If timed correctly, your opponent can interrupt Sub-Zero out of his attack. This can also be done with normal attacks albeit rather difficult.
If there is an interactable in the corner, your opponent will have the option to use it to escape the corner or armor through Sub-Zero’s attack. Finally, Flawless Blocking the Arctic Trap will destroy it and allow your opponent to interrupt the mixup.
All of these options however can be baited and punished, so you will not always want to attack while the Arctic Trap is set up.
The Arctic Trap setup can only be beaten by getting up normally without using a Delayed Getup and interrupting or blocking the Arctic Trap. If blocked, the Arctic Trap will disappear and Sub-Zero will be at -11.
To stay unpredictable, always end your combos with Sub-Zero’s B321. Afterwards, walk back and then quickly walk forward and go for an overhead/low mixup. When your opponent starts to use a Delayed Getup or Roll Escape to avoid the mixup, then you will be able to set up the Arctic Trap. Between B32, F2 and Arctic Trap, you will want to mix up all of your options to keep your opponent guessing on knockdown.