Isn’t it wild Omni-man is able to slice other Viltrumites open with his barehand? Imagine if humans were able to do that to each other, the Viltrumites have an insane amount of trust amongst each other. It also seems to be Nolan’s favourite move as well lol.
The knife hand technique seems to only work with perfect timing/placement. We see it used against stationary opponents (Immortal, Allen), but against a Viltrumite it only worked as a very lucky opportunity attack - and even then only a narrow cut along a straited muscle band.