They read, Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control. That means you can attack in multiple ways, and as long as youre interfering with your opponents hand and board state, youll benefit massively from it
His Mardu colour identity is important too, allowing the deck to break outside of the usual Rakdos colours for vampires and include all the white vampires that have been printed in recent times, as well as providing access to enchantment removal which historically black and red have struggled with
Now the good thing to note here is that this effect does not end after you have cast the first spell
Single card, multi-pack, or MEGA poster doesn't matter
Creating the double-striking Samurai token is just a bonus, but the kind of bonus we can leverage in a Samurai deck