Possible Clues:

• Last short epistle used in uni­versity, after appropriate period
• Team Frisbee game
• Last of a multi-tea blend
• Utmost
• University returns it to comrade as the best achievable
• Last or final
• Extremists taken out in full, the enemy's imprisoned at last
• Metal, it made earlier units last
• Final; last
• Final is not altogether difficult -- I'm at ease