Activate Karrthus, putting a token copy of Karrthus onto the battlefield.
The token copy is put into your graveyard due to the legend rule.
The token copy's enter the battlefield ability triggers, untapping all dragons you control.
Repeat.

Infinite death triggers

Infinite ETB

Infinite LTB

Karrthus, Tyrant of Jund

Splinter Twin

Cast Astral Dragon by paying {6}{U}{U}.
When Astral Dragon enters the battlefield, it and Ganax trigger.
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 triggers twice, creating two Treasure tokens.
Activate both Treasures by tapping and sacrificing them, adding {2}.
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 "Karrthus, Tyrant of Jund"