Malcolm, Keen-Eyed Navigator + Leyline of Transformation + Weftstalker Ardent

Prerequisites

You have a way to cause an artifact to enter the battlefield under your control.

Steps

1. Cause an artifact to enter the battlefield under your control.
2. Weftstalker Ardent triggers, dealing 1 damage to each opponent.
3. Malcolm triggers, as Weftstalker Ardent is a Pirate due to Leyline of Transformation, creating a Treasure token for each opponent dealt damage this way.
4. When the Treasure(s) enter, Weftstalker Ardent triggers that many times.
5. Resolve the first Weftstalker Ardent trigger, dealing 1 damage to each opponent.
6. Repeat from step 3.