Barret, Avalanche Leader + Sword of the Meek + Queen Allenal of Ruadach + Phantom Train
Barret, Avalanche Leader
Sword of the Meek
Queen Allenal of Ruadach
Phantom Train
Infinite artifact ETBInfinite artifact LTBInfinite artifact sacrifice triggersInfinite +1/+1 counters on a creatureInfinite creature ETBInfinite creature LTBInfinite creature tokensInfinite death triggersInfinite creature sacrifice triggersInfinitely large creature until end of turn
How it works
Cast Sword of the Meek by paying 2.
When Sword of the Meek enters, Barret's first ability triggers.
Holding priority, activate Phantom Train by sacrificing Sword of the Meek.
Resolve the Barret trigger, creating a 2/2 Rebel creature token and a 1/1 Soldier creature token due to Queen Allenal of Ruadach.
When the Soldier enters, Sword of the Meek triggers, returning itself from your graveyard to the battlefield attached to the Soldier.