Negative Energy Six-Star Ball (BT12-117) - Vicious Rejuvenation

[Permanent] This card can't attack and isn't affected by your opponent's skills.
[Activate:Main] If your Leader Card is a "Shadow Dragon" card and you place this card in its owner's Drop Area : Choose up to 1 "Oceanus Shenron" card with an energy cost of 2 in your deck or hand, play it, then shuffle your deck if you looked through it.