Labs Aang's Journey Aang, Master of Elements Aardvark Sloth Abiding Grace Absolving Lammasu Absorb Abuna's Chant Abundant Maw Act of Aggression Adorable Kitten Adventurer's Inn Aerial Assault Aerial Predation Aerial Responder Aerith Gainsborough Aetherflux Reservoir Ageless Entity Airdrop Aeronauts Ajani Goldmane Ajani Vengeant Ajani's Mantra Ajani's Pridemate Ajani's Sunstriker Ajani's Welcome Ajani, Inspiring Leader Ajani, Mentor of Heroes Ajani, Sleeper Agent Ajani, Strength of the Pride Ajani, Wise Counselor Ajani, the Greathearted Akoum Refuge Alabaster Mage Alert Heedbonder Alhammarret's Archive Alive // Well Alive // Well Alquist Proft, Master Sleuth Altar of the Pantheon Amateur Hero Amazing Alliance An Incident Has Occurred An-Havva Inn Ancestor Dragon Ancestor's Chosen Ancestor's Prophet Ancestral Tribute Ancient Cornucopia Angel of Destiny Angel of Mercy Angel of Renewal Angel of Vitality Angel's Feather Angel's Mercy Angelheart Vial Angelic Chorus Animal Boneyard Anodet Lurker Anointed Chorister Anointer Priest Answered Prayers Ant-Man's Army Apothecary Geist Apothecary Initiate Apothecary Stomper Apothecary White Appetite for the Unnatural Approach of the Second Sun Arabella, Abandoned Doll Aragorn and Arwen, Wed Arashin Cleric Arbaaz Mir

If you look at the original printing of cards like Elvish Champion, Troll Ascetic, or Thrun, the Last Troll, youll see that regeneration was a classic way to ensure those creatures stuck around
In this case, though, I think its more than fair
Black-Red features the set's other new mechanic, Mayhem, which lets you play cards for cheap from your graveyard if you discarded them on the same turn