"At least my hatred keeps me strong. Your attachments make you weak, brother-- they're gaping holes in your defenses just waiting to be exploited."

And strength was what mattered. Strength always mattered, because Liquid had to be strong to be worthy, to not be inferior. He had to be strong and hard and unyielding as steel.

"The only reason I kept him with me is because I knew you would come to him."

And the only reason Otacon had stayed with him was because he wanted to protect Snake. And here Liquid had almost started to believe all of that friends bullshit.