Bladewing the Risen, and Dack's Duplicate

Prerequisites

• Bladewing the Risen on the battlefield
• Dack's Duplicate in hand

Steps

1. Cast Dack's Duplicate by paying its mana cost, choosing to have it enter the battlefield as a copy of Bladewing
2. Put Bladewing into your graveyard due to the legend rule
3. Dack's Duplicate's enter-the-battlefield ability triggers, returning Bladewing from your graveyard to the battlefield
4. Put Bladewing into your graveyard due to the legend rule
5. Bladewing's enter-the-battlefield ability triggers, returning it from your graveyard to the battlefield
6. Repeat from step 4

Results

• Infinite LTB
• Infinite ETB
• Infinite death triggers