This loop is set into motion by the passive presence of Spider-Man, Peter Parker, whose ability transforms any incoming lifegain into fuel by placing a +1/+1 counter and granting indestructible to a creature you control. By activating Benthic Biomancer, you trigger its loot effect when the counter lands, which naturally helps fill your graveyard to easily satisfy Starving Revenant's descend 8 condition. Once that threshold is met, the card draw from Benthic Biomancer triggers Starving Revenant to drain your opponent and gain you life, which in turn wakes up Spider-Man, Peter Parker to distribute another +1/+1 counter back onto Benthic Biomancer to keep the engine turning.