Round 0 - Surprise round: Guts tries to take Wizard by surprise and fails to do so, With the wizards unbeatable initiative score means he goes second with no exceptions.
Wizard: Takes a look at Guts and knows every piece of relevant information, from the magical properties of his equipment, to his lack of casting ability. Wizard decides to job the fight instead of instantly killing him. Standard action: Disjunction, Swift action: Quickened Dimension door to teleport 1200 ft straight up.
Effect: The berserk armor is now just regular armor, the dragonslayer is now a +0 mwk greatsword. Fortunately his bombs, Knives and crossbow are mundane in nature and are not affected.
Guts: Being reduced to an angry cripple with crappy items, Guts spends a standard action (Surprise round so no full attacks) shooting at the wizard.
Effect: Range penalties ensure on a miss except for nat 20s. Can tank the lucky shot no prob.
Round 1:
Wizard: Swift action: Quickened Fickle winds, Move action: take out cl1 wand of magic missile that he found back when he was level 4, Standard action: Reach spell Shatter to destroy the cannon arm
Effect: The arm is no more, crossbow falls to the ground, the swirly air allows guts a generous view of wizard pants.
Guts: move action: pick up his crossbow which was conveniently left intact, standard action to shoot at the Wizard while looking very angry.
Effect: Bolts are deflected by the fickle winds with no ifs, buts or maybes.
Round 2:
Wizard: Free action: Chuckles to himself, Swift action: Quickened Dimension door to teleport 80 ft above Guts, Standard action to activate the wand and hit guts for 1d4+1 damage.
Effect: Guts takes 1d4+1 damage because there is no save nor can it be dodged.
Guts: Full round action: Full attacks with his crossbow, no effect.
Round N: Wizard keeps tormenting guts with 1d4+1 damage and switches to another wand when he uses up the 50 charges, guts eventually dies after a slow and humiliating battle.