Possible Clues:

• Activity that involves proving your chops?
• Combat tradition
• Wrestling with a painting of those fighting in the GPO in 1916, for one
• Tai chi, for example
• Aikido or capoeira, e.g
• Karate, for one
• Contact sport for which war paint could be used?
• Dojo activity
• Skilled defence, to spoil a trial badly ahead of time
• Kung fu, e.g.