Magmakin Artillerist triggers, dealing 1 damage to each opponent and causing you to gain life.
Archangel of Thune triggers putting a +1/+1 counter on each creature you control.
Repeat from step 2.
This loop transforms a single +1/+1 counter into a devastating feedback engine by turning Benthic Biomancer's looting ability into a self-sustaining trigger. As Benthic Biomancer cycles cards through your hand, Magmakin Artillerist weaponizes those discards to deal direct damage to your opponents. That damage naturally triggers Archangel of Thune's lifelink-driven blessing, bolstering your entire board with new +1/+1 counters that restart the whole cycle anew.