
Well, Horus remembers what Sekhmet said because he now understands Seth's feelings and behavior are all basically like the ones of "a cornered animal". Horus remembering Sekhmet's words right now serves to show readers why he's not resenting Seth for trying to kill him right now: he knows now for sure that his extreme angry reactions and lashing out are not because Seth's evil, but rather just because he's afraid and he feels threatened. And the reason he feels this threatened and afraid is because he's lost faith in his own strength. This is a weakness because it induces Seth to do extreme things that he would later regret, and moreover it causes the people he lashes out at, like Isis, to react with extreme actions in response, causing a chain-reaction that could end up getting Seth killed by the actions a desperate victim like Isis could set in motion, out of sheer desperation. Horus has realized that every time Seth lashes out at others, he sets in motion a vicious cycle of action and reaction, revenge and counter revenge, that would only end up getting many people really hurt in the process (among them, also Seth himself) and Horus' finally realized he needs to put a stop to it before it gets out of control and the consequences become irreversible.
can someone explain what sekhmet meant at the end because if set’s weakness is his own doubt then i don’t understand what that had to do in that situation