Activate Skirge Familiar by discarding Darkblast, adding {B}.
Bone Miser's third ability triggers, causing you to mill three cards and return Darkblast from your graveyard to your hand.
Repeat.

Infinite self-mill

Near-infinite black mana

Near-infinite self-discard triggers

Bone Miser

Darkblast

Skirge Familiar

Attempt to draw card, instead choosing to mill 3 cards and return Darkblast from your graveyard to your hand.
If you milled a nonland card, The Wise Mothman triggers, putting a +1/+1 counter on Benthic Biomancer.
Benthic Biomancer triggers, causing you to draw a card and discard Darkblast.
Repeat.

Benthic Biomancer

The Wise Mothman

Attempt to draw a card. The draw will be replaced by Chains of Mephistopheles, causing you to instead discard Darkblast. Then, you will mill three cards and return Darkblast from your graveyard to your hand due to Darkblast's dredge ability.
Bone Miser's third ability triggers, attempting to have you draw a card. The draw will be replaced by Chains of Mephistopheles, causing you to instead discard Darkblast. Then, you will mill three cards and return Darkblast from your graveyard to your hand due to Darkblast's dredge ability.
Repeat step 2.

Combos with "Darkblast"