Text (SM): 1/1, Fear. ; {2}{U}{B}: Each unblocked creature becomes 4/1 until end of turn.
A creature is only "unblocked" during combat after blockers are declared. Playing the ability prior to the declaration of blockers or after combat ends will affect no creatures. [Shadowmoor FAQ 2008/04/21]
Although the creatures stop being unblocked at the end of combat, they will remain 4/1 until end of turn. [Shadowmoor FAQ 2008/04/21]
Setting power/toughness to 4/1 overrides most other power/toughness setting effects, except: ones that alter or set power/toughness and are applied after this resolves; counters that alter power toughness (even if they are played before this resolves); static abilities that change power/toughness such as Glorious Anthem (even if they were played before this resolves); and effects that switch power/toughness. [Shadowmoor FAQ 2008/04/21]
