Since Kasady is a cold-blooded murderer, Carnage is more vicious than Venom, and hence doesn't have some of the barriers that Venom has shown in the comics and the movie. In an interview with IGN ...

The major draw remains Tom Hardy’s dual ... for a villain of substance (certainly not one movie after Venom faced down his most famous foe, Carnage.) Knull is rarely seen, seldom spoken about ...