Dragon Tempest, and Ancient Gold Dragon

Prerequisites

• Dragon Tempest on the battlefield
• Ancient Gold Dragon on the battlefield
• Ancient Gold Dragon does not have summoning sickness and cannot be blocked by an opponent

Steps

1. Deal combat damage using Ancient Gold Dragon
2. Ancient Gold Dragon triggers, causing you to roll a d20 and create that many 1/1 Faerie Dragon creature tokens
3. When the Faerie Dragons enter the battlefield, Dragon Tempest's second ability triggers that many times
4. Resolve the first trigger, dealing damage to any target equal to the number of Dragons you control
5. Repeat step 4 for each remaining trigger

Results

• Near-infinite damage