How to destroy a GameObject after changing Scenes?

So this is my problem…

My level runs on a Scene, it has enemies and collectables, let’s call it Scene A.
When you touch an enemy it switch to a Battle Scene, it has the player and the enemy you touched, it also has buttons as attacks, just like Pokemon style. Let’s call it Scene B.

After defeating an enemy it switch back to Scene A, but the enemy is still there and all the items that had been collected too.

How can I fix this problem ?

Make a public class, add a DontDestroyOnLoad, whenever you defeat it, add the enemy to a master list (thats transferred between scenes), OnLevelLoad, parse through list of defeated enemies, and remove respectively.