The Tenth Doctor, Mana Echoes, Arc Blade, and Lord of the Nazgûl

Prerequisites

• The Tenth Doctor on the battlefield
• Mana Echoes on the battlefield
• Arc Blade in exile
• Lord of the Nazgûl on the battlefield
• available

Steps

1. Activate The Tenth Doctor by paying , removing all time counters from Arc Blade
2. Arc Blade triggers, causing you to cast it from exile without paying its mana cost
3. Lord of the Nazgûl triggers, creating a creature token
4. When the creature token enters, Mana Echoes triggers, adding for each creature you control that shares a creature type with the token
5. Resolve Arc Blade
6. Repeat

Results

• Infinite ETB
• Infinite colorless mana
• Infinite creature tokens
• Infinite damage
• Infinite magecraft triggers