Sorry about a second forum post >.< However, I feel like the sleep status does not really show up in this game.
-The only way to inflict the sleep status is through a vial
-Currently, there is no way to truly receive it
Where would you like to see this status? (Note: The status makes the receiver unable to move, but they gain a small amount of health over time)
-A sword/handgun/bomb that inflicts it?
-A monster that inflicts it?
-A new obstacle (like the ones int he bottom right of the Training Hall)
Actually, you can still get hit with Sleep, it's just very rare. You have to open a Monster Crate to find a Sloom, and let it hit you with Sleep. It doesn't happen very often.