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

Near-infinite damage

Dragon Tempest

Ancient Gold Dragon

Give Vrondiss indestructible by any method.
Deal damage to Vrondiss by any method.
Vrondiss triggers, creating a 5/4 Dragon Spirit creature token.
The Dragon Spirit enters the battlefield, triggering Dragon Tempest, causing the Dragon Spirit to deal damage to Vrondiss equal to the number of Dragons you control.
The Dragon Spirit and Vrondiss trigger.
Resolve the Dragon Spirit trigger, causing you to sacrifice it.
Resolve the Vrondiss trigger, creating a 5/4 Dragon Spirit creature token.
Repeat from step 4.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Vrondiss, Rage of Ancients

Cast Astral Dragon by paying {6}{U}{U}.
When Astral Dragon enters the battlefield, it and Ganax trigger, along with Dragon Tempest's first and second abilities.
Resolve the Ganax trigger, creating a Treasure token.
Activate the Treasure by tapping and sacrificing it, adding {1}.
Activate Strionic Resonator by paying {2} and tapping it, copying Astral Dragon's ability, targeting Strionic Resonator.
Resolve the copy of Astral Dragon's ability, creating two token copies of Strionic Resonator that are 3/3 Dragons in addition to their other types.
When the Strionic Resonator tokens enter the battlefield, Ganax's ability, as well as Dragon Tempest's first and second abilities, trigger twice each.
Resolve both Ganax triggers, creating two Treasure tokens.
Activate both Treasures by tapping and sacrificing them, adding {2}.
Resolve both of Dragon Tempest's first ability triggers, giving the Strionic Resonator tokens haste until end of turn.
Resolve both of Dragon Tempest's second ability triggers, dealing damage equal to the Strionic Resonator tokens' power to any target.
Activate a Strionic Resonator copy by paying {2} and tapping it, copying Astral Dragon's ability from step 2.
Repeat from step 6.

Combos with "Dragon Tempest"