The suggested build sounds reasonable.
You also might be able to play a different race. 16 strength and a blade weapon sounds well enough. Focus on wisdom and int instead of dex and charisma is probably the best choice. But charisma and using some illusions doesn´t look that wrong:
so my suggestion:
====== Created Using Wizards of the Coast D&D Character Builder ======
Warryn, level 5
Gnome, Barbarian|Wizard
Hybrid Talent: Barbarian Armored Agility
Background: Gnome - Fomorian Captivity (+2 to Endurance)
FINAL ABILITY SCORES
Str 17, Con 12, Dex 8, Int 19, Wis 10, Cha 14.
STARTING ABILITY SCORES
Str 16, Con 12, Dex 8, Int 16, Wis 10, Cha 12.
AC: 21 Fort: 17 Reflex: 18 Will: 16
HP: 44 Surges: 8 Surge Value: 11
TRAINED SKILLS
Perception +7, Endurance +9, Arcana +13
UNTRAINED SKILLS
Acrobatics, Bluff +4, Diplomacy +4, Dungeoneering +2, Heal +2, History +6, Insight +2, Intimidate +4, Nature +2, Religion +6, Stealth +2, Streetwise +4, Thievery, Athletics +4
FEATS
Level 1: Hybrid Talent
Level 2: Gnome Phantasmist
Level 4: Phantom Echoes
POWERS
Hybrid Barbarian at-will 1: Howling Strike
Hybrid Wizard at-will 1: Illusory Ambush
Hybrid encounter 1: Grasping Shadows
Hybrid daily 1: Horrid Whispers
Hybrid utility 2: Shield
Hybrid encounter 3: Blood Strike
Hybrid daily 5: Ancient Berserkers' Rage
ITEMS
Adventurer's Kit, Implement, Wand, Magic Longsword +2, Barkskin Hide Armor +1, Cloak of the Lion's Mane +1
====== Copy to Clipboard and Press the Import Button on the Summary Tab ======
definitely not optimized... but could be fun...