Tortured Existence by paying ({B} magic symbol) and discarding a creature card, returning
Revolutionist from your graveyard to your hand.
Activate
Tortured Existence by paying ({B} magic symbol) and discarding
Revolutionist.
Revolutionist is discarded into exile instead of your graveyard due to its madness ability, causing you to pay ({3} magic symbol) ({R} magic symbol) to cast
Revolutionist for its madness cost.
When
Revolutionist enters the battlefield, it triggers, returning
Burnt Offering from your graveyard to your hand.
Resolve the
Tortured Existence ability from step 3, returning a creature card from your graveyard to your hand.