Crobat's Roost

[PokePerfect]

I taught my Crobat Roost and when I used Roost when battling a Sableye with Power Gem, Crobat lost its weakness to Rock. However, after I used a move other than Roost, Crobat was weak to Power Gem again. Why is that?

 

[pplzdude]

"Roost restores half of the user's maximum HP. If the user is a Flying-type, it will lose its Flying-type (thus being treated as a single-type Pokémon) until the next turn. If a non-Flying-type uses Roost, then there are no side effects."

 

[Matt_192]

I taught my Crobat Roost and when I used Roost when battling a Sableye with Power Gem, Crobat lost its weakness to Rock. However, after I used a move other than Roost, Crobat was weak to Power Gem again. Why is that?

Roost means that you lose your flying type for that turn - then you will regain it on the turn following :]