(Flip monsters' effects are not activated at this time, except "Shaddoll" monsters'.) You can only use 1 "Shaddoll Hound" effect per turn, and only once that turn
In fact, when Dragon-link decks rose to notoriety recently, Buster Blader decks had a slight resurgence, as they were the perfect way to punish your opponent for summoning a whole bunch of dragons
Despite this, the official English anime website still lists the Nordic Gods as DIVINE Divine-Beast monsters
If it does, apply its ATK for damage calculation
Thats not if its destroyed by a card effect too, thats just if it leaves the field by a card effect, making it incredibly easy to disrupt the Dark Magician gameplan
Returning it to hand, banishing it, or even using it as synchro material (as unlikely as that is), all of it counts