Due to the streamlining of spells and combat arts from levels 1-20, specifically several changes to fighter spells and arts, Fighter classes are finding it difficult or impossible to complete Heroic Opportunities.
Game Update 57 will see some changes to fighter classes to resolve this issue. From Xelgad on the EQ2 Forums:
Fighter heroic opportunities have been changed from requiring a taunt to complete them to requiring a ‘Fist’ icon to complete them. Paladins and Shadowknights should soon see that one of their primary spells is now a Fist rather than a sword (Judgment and Malice) and Berserkers will soon see that Body Check and Raging Blow now go up to Raging Blow/Body Check VIII, rathar than VII, and they receive those spells at levels two and three.
Everyone should be able to complete their solo heroic opportunity without toggling a buff or a stance as soon as the rest of the changes make it to test.
Now they just need to make sure skills like aggression start at 100 when the first taunt is gained.