What is done with a killer when sentenced to the discretionary punishment (ta'zir), and is his neck struck more than once, or is the sword plunged into the neck area after it has been severed?

If a person kills another aggressively, the guardians of the victim's blood (awliya' al-dam) are entitled to retaliate by killing the aggressor, unless they pardon him. In this case, scholars have differed: the majority view is that he is not punished, whereas the Malikis hold that he is to be flogged one hundred lashes and imprisoned for one year, by analogy with the un-stoned fornicator who did not kill due to not being muhsan (a married person who has had sexual intercourse).