Dross Scorpion, Elemental Mastery, Phantom Train, and Mycosynth Lattice

Prerequisites

• Dross Scorpion on the battlefield
• Elemental Mastery on the battlefield
• Phantom Train on the battlefield
• Mycosynth Lattice on the battlefield

Steps

1. Activate the creature with Elemental Mastery attached by tapping it, creating a number of 1/1 Elemental creature tokens with haste equal to its power
2. Activate Phantom Train by sacrificing an Elemental
3. When the Elemental dies as an artifact due to Mycosynth Lattice, Dross Scorpion triggers, untapping the creature with Elemental Mastery attached
4. Resolve the Phantom Train ability
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite creature tokens with haste
• Infinite +1/+1 counters on a creature