According to MTG Hall of Famer Frank Karsten, versus a typical Pioneer mono-red deck, Sphinxs Tutelage and The Water Crystal have an 82.6% chance to repeat the process 7 times, which is enough to mill your opponents library
Bloated Contaminator trumps this card in terms of mana efficiency (spoilers), but Grafter provides card draw and ramp, something poison-based decks are severely lacking
While there may be more powerful cards for similar effects, such as Endless Ranks of the Dead or Liliana, the Last Hope, Relentless Advance can still be a solid inclusion in decks looking to amass a formidable army of undead creatures
Protection doesnt stop your opponent from winning the game if they meet the conditions to do so, such as with an alternate win condition
If you've already used Pokemon Pocket 's reroll exploit, you're likely familiar with the account-switching process, as they are essentially the same