You select the monster when you activate "Micro Ray".
If you apply "Micro Ray"'s effect and then a new card increases the DEF, add the new DEF to the zero.
You can activate "Micro Ray" during the Damage Step.
You select the monster when you activate "Micro Ray".
If you apply "Micro Ray"'s effect and then a new card increases the DEF, add the new DEF to the zero.
You can activate "Micro Ray" during the Damage Step.