SB-SE05-36

" 【AUTO】 When "Azure Oni" is played in your climax area, if you have 1 or fewer other characters in your front row, look at the top 5 cards of your Opponent's deck and choose up to 5 of them and put them in your Opponent's waiting room. Return the rest to your Opponent's deck, and shuffle That deck afterwards, and all your "Weapon" Characters gain 2000 Until End power of your Opponent's next turn."

So does this mean his effect stack if I have multiple on my stage?

Like if I had 2 in the front row and declaring a front attack, would I mill up to 5 first, shuffle, mill 5 again and the same would apply to the other Masamune Date? Or is it just mill 5 for one attack?