Mulligans
This decks aims to combine all of the deathrattle synergies with Reckless Experimenter and Zerek's Cloning Gallery to overwhelm the opponent.
Early game: Play Northshire Cleric, Power Word: Shield, and Dead Ringer to contest the board and draw cards. Use Shadow Word: Pain and Spirit Lash when necessary against aggro. Use Stonehill Defender and the resulting taunts to last until the mid game.
Mid-game: Begin to utilize the deathrattle synergies. Reckless Experimenter cobines well with Devilsaur Egg, Mechanical Whelp, and to a lesser extent, Coffin Crasher. Use Binding Heal and Vivid Nightmare on Zerek, Master Cloner.
Late game: Spiritsinger Umbra can be combined with any of the other deathrattle cards. Close the game out with Zerek's Cloning Gallery.
Utility: Shadow Word: Death is included for single target removal. Twilight's Call can be played at any point after a couple deathrattle minions have died. Mass Dispel is used for silence and card draw. Psychic Scream is included as a safety tool if necessary.