Well, I guess it would have a tier change and there is also a strategy that can also cause a tier change with Slaking. Slaking has to be on a team with Desukan. Have Desukan take a hit from a contact move to give the Mummy ability to its opponent, then send in Slaking. Then just use Pursuit to hit them even if they switch and discard Slaking's Truant ability for Mummy, and sweep.
