Roger Smith, Negotiator

At the beginning of each upkeep investigate.

Whenever a creature an opponent controls attacks, you may pay {w/u}{w/u} and sacrifice a clue. If you do, untap that creature and remove it from combat, then the attacker and defender may each draw a card.

{4},sacrifice 4 clues: Create Big O, a legendary 8/8 black artifact creature token with haste, vigilance, and '{t}:This creature gets +4/-4 until end of turn'. Sacrifice it at the beginning of the next end step.