((Considering how I was the one who came up with the whole "Aura sensing" and even taught it to Leon in a private RP which took place before this, I think I should explain. Everyone has aura, inside of them. Aura is the literal energy of life, and unless you are dead, you have it. Ghost and spirits don't have Aura, because they are dead. The undead count as living as well. It's fairly difficult to mask an energy which I can only assume Fout doesn't understand, and can't exactly control or manipulate, unlike Leon. And even then, Leon wouldn't be able to hide his aura. That's how he would've picked up on Fout.))