When Dualcaster Mage enters the battlefield, it and Blasting Station trigger.
Resolve the Blasting Station trigger, untapping it.
Resolve the Dualcaster Mage trigger, copying Black Sun's Twilight, optionally choosing to target a creature.
Holding priority, activate Blasting Station by tapping it and sacrificing Dualcaster Mage, dealing 1 damage to any target.
Resolve the copy of Black Sun's Twilight, giving up to one creature -5/-5 until end of turn and returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
Results
Infinite LTB.
Infinite ETB.
Infinite sacrifice triggers.
Infinite death triggers.
Infinite damage.
Infinite magecraft triggers.
Reduce any number of target creatures' toughness to zero.