Lu Meng - Level 11 Weapon | Dynasty Warriors 4 Xtreme Legends (4K, 60fps) 

One of the easiest ones to get and is basically the same requirements as his Lvl 10 weapon
Difficulty: Expert
Stage: Siege of Mai Castle
Restrictions: None
Requirements: Defeat Liao Hua, Zhou Fang, Guan Ping and defeat 50 enemies.
Tips: Really simple, just save before fighting Guan Yu as he can reck you from off of the screen