Sion listens as Marik explains, quickly mentally filing away each new piece of information. The explanation of the life points certainly would be a good reason why having monsters fielded quickly would be important, he can see.

"I take it this device will automatically track those points, rather than the players having to do so themselves?"

Since if they're having to do it manually, scrounging up something to write with may be in order.

"Let's go with heads."