Possible Clues:

• Deft enough to be dead when beheaded
• Expert
• Showing expertise
• Expert, adroit
• Knowing such a workman
• Training is needed to have put an end to the South like this
• Well-trained decapitation leads to death
• Competent to have polished one off by beheading
• Professional done in by end of aerobics
• Showing great aptitude