Here's an example 12th level character using this build; sources used are PHB, PHB2, Complete Arcane, DMG, this class, Skip Williams' suggestion on Practiced Invoker, and Dodge gives a +2 bonus instead of +1.
Brandishertestsubject
Human; Warlock 6 / Fighter 1 / Brandisher 5
elite monster array for attributes
Str- 15 +2 levels +4 enhancement = 21 (+5)
Dex- 13 +1 levels +2 enhancement = 16 (+3)
Con- 14 +2 enhancement = 16 (+3)
Int- 12
Wis- 10
Cha- 08
Base Attack: +10 / +5 AC: 10 +3dex +10arm +3shield +2def (+2dodge) = 28 (30)
Saves: Initiative: +3
Fort +13 Hit Points: 42+5d6+5d8+1d10
Ref +8 Speed: 8 squares (5 in armor)
Will +11 Alignment: Chaotic Good
Skill Ranks: Bluff 5, Concentration 5, Intimidate 15, Knowledge (arcana) 5, Knowledge (the planes) 5, Knowlege (relgion) 5, Listen 5, Spellcraft 15, Spot 5, Tumble 2, Use Magic Device 1
Feats: Dodge1h, Combat Reflexes1, Battle Caster (medium)3, Spell Penetration6, Weapon Focus (great sword)7f, Practiced Invoker9, Improved Buckler Defense9f, Greater Spell Penetration12
Special: eldritch blast 6d6, detect magic at will, DR 1 / cold iron, deceive item, hideous brandish, eldritch power +3, hideous flurry
Languages: Common, Celestial
Invocation Caster Level: 12 (+4 for breaching spell resistance)
Invocations Known:
Least- hideous blow, see the unseen, leaps and bounds
Lesser- brimstone blast, fell-flight, walk unseen, eldritch chain
Equipment/Money (standard wealth by level 88,000gp):
635gp
Girdle of Giant Strength +4 (16,000gp)
Greatsword +2 (8,000gp)
Mithral Fullplate +2 (14,500gp)
-Masterwork Armor Spikes (350gp)
Mithral Buckler +2 (5,015gp)
Cloak of Resistance +2 (4,000gp)
Bracers of Constitution +2 (4,000gp)
Gloves of Dexterity +2 (4,000gp)
Boots of Striding and Springing (5,500gp)
Ring of Protection +2 (8,000gp)
Greater Chasuble of Fel Power (18,000gp)
Attacks:
Hideous Flurry (sword)- +10 (base) +2 (enhance) +1 (feat) +5 (strength) +3 (eld pwr) = +21 / +13
2d6+9 slashing plus 8d6 eldritch blast
Hideous Flurry (spikes)- +10 (base) +1 (enhance) +5 (strength) +3 (eld pwr) = +19 / +11
1d6+5 piercing plus 8d6 eldritch blast
Eldritch Blast/Chain- +10 (base) +3 (dex) (+3 eld pwr if needed) = +13 ranged touch
8d6+3 non-typed energy or fire