(2) When your Azamina or White Forest monster destroys an opponents monster by battle: You can target 1 Sinful Spoils Spell/Trap in your GY
In fact, the problem got so bad that at one point, we had a Standard format where there wasn't a single card available to interact with the graveyard (and this format was unsurprisingly dominated by Emrakul, the Promised End and other graveyard-based decks)
Incapsula incident ID: 567000120636997949-1313621305206440756
After Future Sight, there is very little new info released about the Elder Dragons
I could definitely see the value in running 1 to 2 mainly because of how much harder it makes it to remove a Sengir Vampire or deal with it in combat, but I chose to omit them because they are expensive, I dont own them, and they dont seem necessary
You may have a super rare card, but if it looks like your dog has chewed on it then it is unlikely to be worth very much