Activate Altar of Dementia by sacrificing Ruthless Ripper.
When Ruthless Ripper dies, Missy's first ability triggers, returning Ruthless Ripper from your graveyard to the battlefield face down as a 2/2 Cyberman artifact creature.
Resolve the Altar of Dementia ability, causing target player to mill cards equal to Ruthless Ripper's power.
Activate Ruthless Ripper's morph ability by revealing a black card from your hand, turning it face up.
Ruthless Ripper triggers, causing target player to lose 2 life.