Text (5th+errata): 2/5. ; At end of combat, gain control of all creatures blocking ~this~ for as long as you control ~this~. [Oracle 2009/07/08]
This means it affects ones currently being blocked by this card at the end of combat and not ones that might have been removed by an effect such as General Jarkeld. [Duelist Magazine #8, Page 47]
If The Wretched blocks and regenerates, it is removed from combat, so The Wretched will not be blocking anything at the end of combat. This means there will be no creatures blocking it when the triggered ability resolves and so the ability does nothing. [D'Angelo 1999/04/25]
Note - Thie card was creature type "Wretched" until Oracle 2007/10/01, when it became "Demon".
