chess. 40 chapters of deus ex machina chess!
a cannon as his main fighting weapon. He trains his body and strength to perfection, he tempers his iron skin and defenses, he spars with a monstrous instructor every day for hours: all so that he can hold a cannon and fire it inaccurately? And I don't buy the excuse that he can't learn fighting techniques: he learns things in his sleep and in 10x speed, there must be some room for him to learn some saber techniques and such.