You can still lose the game for other reasons, including having ten or more poison counters or drawing a card from a library with no cards in it
I also love this in a Saga deck to bring back dead Sagas
Tidus, Yunas Guardian has the ability to move a counter from any target creature onto another target creature, and hes also got the unique Cheer ability, which allows him to draw cards and proliferate whenever one or more creatures (that the player controls) deals combat damage
Once the board is open and Ruhan sufficiently suited up with our armory (Obsidian Battle-Axe, The Reaver Cleaver, etc.) and auras (Steel of the Godhead, Mantle of the Ancients, etc.), we can further ensure opponents are vanquished in timely fashion by copying our Commander via cards like Helm of the Host and Irenicus's Vile Duplication, which ignore the Legendary rule
Face-down cards add an intriguing level of suspense as your opponents must navigate a board filled with face-down cards that could be anything