This Warlock is casting curse of weakness against an orc foe. In D&D 4e, curse of weakness would be a per encounter power instead of an at will power. In 3e, it's a spell that can be cast that reduces strength, sort of like ray of enfeeblement.
The morph is Jammin'Wolfie's Tindra Thompson, and the orc is Ghost of MacBeth's War Orc morph for M4/F4. Fun, eh?