Steelswarm Scout's role in the Steelswarm Army was obviously to spy on the enemy and return to his superiors with learned information. He was sneaky and knew a great deal of making himself seem inconspicuous. Because of this, Scout was easily able to tell what it was that the new and shady looking duelist was doing each time he "yawned". 

*Psst, hey Lars...*

Scout whispered in Lars' left ear to tell him of what he just saw. 

"Doing a bit of recon himself, huh? Not surprised, I'd want to know what I'm up against too."

Lars thought about switching his main deck with his Archfiend one. It would give off a false impression to the spying duelist and to anyone who was trying to scope him out. Then again, what good would it really do? By the looks of this guy, he was probably from the Obsidian District, or at the very least lived there for a time. If that was so, then he probably already knew what he used. Oh well, didn't hurt to do as such. Besides, if there were any premature challengers out here, it'd help in not giving away his moves. Also, the old Archfiends needed another whirl. He turned his back and switched decks quickly. 

*Don't call the King over.... he scares me...*

"Well his is called Terrorking for a reason. Relax, he rarely ever comes to me, it's Heiress or Stygian you need to concern yourself with."