Does the effect of Buster Blader work for all graveyards in Yu-Gi-Oh?

Buster Blader's effect only works on your graveyard.

Specifically, Buster Blader's effect states: "If this card is Normal or Special Summoned: You can target 1 monster in your Graveyard; Special Summon it."

It doesn't affect the opponent's graveyard.