Daemonic Control (4e Feat)
From D&D Wiki
Daemonic Control [Racial Feat]
Through the strength of will only an adventurer could muster you have found that you can call upon your innate magical powers more often.
Benefit: You can now use both encounter powers from your Dual Heritage traits once per encounter or can use one of them twice.
Special: If you did not take two encounter powers you can use your Dual Heritage (Fey) power twice.