The Tenth Doctor, Mana Echoes, Reality Strobe, and Metallurgic Summonings

Prerequisites

• The Tenth Doctor on the battlefield
• Mana Echoes on the battlefield
• Reality Strobe in exile
• Metallurgic Summonings on the battlefield
• available

Steps

1. Activate The Tenth Doctor by paying , removing all time counters from Reality Strobe
2. Reality Strobe triggers, causing you to cast it from exile without paying its mana cost
3. Metallurgic Summonings 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 Reality Strobe
6. Repeat

Results

• Infinite ETB
• Infinite colorless mana
• Infinite creature tokens
• Infinite magecraft triggers
• Mass Land Denial
• Return any number of permanents to their owner's hand