Infinite -1/-1 counters, Infinite +1/+1 counters on a creature, Infinite death triggers, Infinite ETB, Infinite LTB, Infinite sacrifice triggers
Activate Bloodflow Connoisseur by sacrificing Soulstinger.
When Soulstinger dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When Soulstinger enters the battlefield, it triggers, putting a -1/-1 counter on it.
Resolve the Bloodflow Connoisseur ability
Repeat.
Component Cards
How It Works
Activate Bloodflow Connoisseur by sacrificing Soulstinger.
When Soulstinger dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When Soulstinger enters the battlefield, it triggers, putting a -1/-1 counter on it.
Resolve the Bloodflow Connoisseur ability
Repeat.