You control creatures that can produce at least ({2} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) .
Sword of Forge and Frontier attached to a creature that can attack and not be blocked.
Steps
Deal combat damage with the creature that Sword of Forge and Frontier is attached to.
Sword of Forge and Frontier triggers.
In response, activate creatures you control by tapping them, adding at least ({2} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) .
Activate Tawnos by paying ({U} magic symbol) ({R} magic symbol) and tapping them, copying the ability of Sword of Forge and Frontier.
Cast Activated Sleeper by paying ({2} magic symbol) ({B} magic symbol) , choosing not to copy anything.
Activated Sleeper enters the battlefield and dies.
Mortuary and Intruder Alarm trigger.
Resolve Intruder Alarm's trigger, untapping all creatures you control.
Resolve Mortuary's trigger, putting Activated Sleeper from your graveyard on top of your library.
Resolve the copied abiltiy from Sword of Forge and Frontier, exiling Activated Sleeper and one other card from the top of your library, allowing you to play those cards this turn, and allowing yourself to play an extra land this turn.
Repeat from step 3 until there are no more cards left in your library.
Results
Exile your library with the ability to play the exiled cards until end of turn.