Presidential Powers
Vetoes
Line-Item Veto is the ability to cancel out some measures of a provision while approving others. It can help to eliminate wasteful federal spending, however it could give too much power to a president.
Judicial Powers
Reprieve is the postponement of the execution of a sentence. A pardon is legal forgiveness of a crime, pardons must be accepted by the person it is given to.
Emergency Powers
These may grant any additional war powers or other powers in times of emergency. Responding to war emergencies automatically grants presidents these powers. However, "times of emergency" is subjective and this could allow for standing laws to be broken.