Here's my suggestion:
====== Created Using Wizards of the Coast D&D Character Builder ======
level 11
Human, Rogue, Whisperknife
Rogue Tactics: Artful Dodger
Rogue: Rogue Weapon Talent
Background: Arcane Mercenary (History class skill)
FINAL ABILITY SCORES
Str 12, Con 12, Dex 21, Int 14, Wis 10, Cha 18.
STARTING ABILITY SCORES
Str 11, Con 11, Dex 16, Int 13, Wis 9, Cha 15.
AC: 24 Fort: 18 Reflex: 24 Will: 21
HP: 74 Surges: 7 Surge Value: 18
TRAINED SKILLS
Perception +10, Stealth +15, Thievery +15, History +12, Athletics +11, Acrobatics +15, Dungeoneering +10
UNTRAINED SKILLS
Arcana +7, Bluff +9, Diplomacy +9, Endurance +6, Heal +5, Insight +5, Intimidate +9, Nature +5, Religion +7, Streetwise +9
FEATS
Human: Linguist
Level 1: Two-Fisted Shooter
Level 2: Slaying Action
Level 4: Backstabber
Level 6: Slaying Action
Level 8: Skill Swap
Level 10: Action Surge
Level 11: Rogue Weapon Mastery
POWERS
Bonus At-Will Power: Piercing Strike
Rogue at-will 1: Sly Flourish
Rogue at-will 1: Duelist's Flurry
Skill Swap: Tactician's Measure
Rogue encounter 1: Acrobat's Blade Trick
Rogue daily 1: Spinning Blade Leap
Rogue utility 2: Sneak in the Attack
Rogue encounter 3: Jumping Blade Assault
Rogue daily 5: Downward Spiral
Rogue utility 6: Swift Parry
Rogue encounter 7: Cloud of Steel
Rogue daily 9: One Hundred Knives
Rogue utility 10: Combat Tumbleset
ITEMS
Hand Crossbow, Crossbow Bolts (40), Reading Spectacles (heroic tier), Riding Horse, Cape of the Mountebank +1, Dagger (4), Shuriken (5), Footpad's Friend Dagger +2, Panther Spirit Leather Armor +2
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If Dragon Magazine is allowed, and you really want an axe, you can take Versatile Duelist and pick up a broadsword (same stats as a battle axe).