Using C++ in Unreal Engine 4 follow these steps https://docs.unrealengine.com/latest/INT/Programming/QuickStart/index.html and create a FloatingActor class. In addition, add a variable that can be edited in blueprints and the editor. Submit the cpp and h files of that class.

Adding variables to unreal editor

UCLASS()

class AMyActor : public AActor {

GENERATED_BODY()

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Damage")

int32 TotalDamage;

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category="Damage")

float DamageTimeInSeconds;

... };