Grist, Voracious Larva // Grist, the Plague Swarm | Hidden Herbalists | Doubling Season

(and two other cards)

Activate
Yahenni by sacrificing
Body Launderer.
When
Body Launderer dies, its second ability triggers, returning
Grist, Voracious Larva from your graveyard to the battlefield.
When
Grist, Voracious Larva enters the battlefield, it triggers, causing you to pay ({G} magic symbol) to exile it and return it to the battlefield as
Grist, the Plague Swarm with six loyalty counters due to
Doubling Season.
Resolve the
Yahenni ability.
Activate
Grist, the Plague Swarm's third loyalty ability by removing six loyalty counters from it.
Grist, the Plague Swarm is put into your graveyard as a state-based action due to having zero loyalty.
Resolve the
Grist, the Plague Swarm ability, creating two token copies of each creature card in your graveyard that are 1/1 Insects.
Put all but one of the
Grist, Voracious Larva tokens into your graveyard due to the legend rule.
When the
Grist, Voracious Larva and Hidden Herbalist tokens enter the battlefield, each Hidden Herbalist token triggers once and each
Grist, Voracious Larva token triggers for each token created this way.
Resolve all
Grist, Voracious Larva triggers, choosing not to pay.
Resolve both Hidden Herbalist triggers, adding ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Activate
Yahenni by sacrificing the
Grist, Voracious Larva token.
Repeat from step 1, sacrificing a
Body Launderer token instead.