Then Sap should include the following...
Allowable in combat,
Does not require Stealth,
If the target was in combat at the time Sap lands...
A (12 second?) CD is placed on Sap
Places a (1 minute?) debuff called Awareness on the target after they regain control, preventing them from being sapped again.
Before people chime in saying it is OP, let me remind everyone of what Sap already does, and how these won't be changed.
Costs 65 energy (reduced with talents)
Still limited to 4 different mob types
Still limited to 1 target
Still breaks on damage