Cast Corpse Dance by paying its mana cost, targeting any applicable target.
Holding priority, cast Dualcaster Mage by paying its mana cost.
When Dualcaster Mage enters, it triggers, targeting Corpse Dance.
Holding priority, activate Woe Strider by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Corpse Dance, with the copy targeting Dualcaster Mage
Resolve the Corpse Dance copy, returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
This cunning loop begins when you cast Corpse Dance, holding priority to flash in Dualcaster Mage whose entry trigger targets the original spell. Before the copy resolves, you sacrifice Dualcaster Mage to Woe Strider to feed its scry ability and tuck the mage safely back into the graveyard. The resulting Corpse Dance copy then pulls Dualcaster Mage right back onto the battlefield, creating a perpetual motion machine of recurring enters-the-battlefield and sacrifice triggers that continuously fuels itself.