Since summoning monsters drains life force, the losing Duelist faints or dies. It is heavily implied only Millennium Item bearers can use a DiaDhank without being limited by life energy. Notice that DiaDhanks were seen in the final season of Yu-Gi-Oh!, and, in Yu-Gi-Oh! GX, Abidos the Third (the fifth Shadow Rider) used a DiaDhank in flashbacks Dueling his servants in episode 40. In the vision that Yami Yugi saw in his Duel with Dartz he did not use his DiaDhank to summon Obelisk the Tormentor. Rather, he used his Millennium Puzzle to summon Obelisk. Also, in the vision that Kaiba and Yami Yugi saw in episode 132, both Priest Seto and Pharaoh Atem used their Millennium Items.