You might be hard pressed to come up with as effective a swordmage/warlock hybrid as the paladin/warlock hybrid below. A wizard/swordmage is another kettle of fish however. Anyway, something to gnaw on while you mess around with your own builds
The Cursed One, level 11
Human, Warlock|Paladin, Student of Caiphon:
Warlock Radiant Powers crit on 18-20
Eldritch Pact (Hybrid): Star Pact (Hybrid):
Required for Student of Caiphon Paragon Path
Eldritch Strike: Eldritch Strike Charisma
Hybrid Warlock: Hybrid Warlock Reflex
Hybrid Paladin: Hybrid Paladin Fortitude
Hybrid Talent: Paladin Armor Proficiency:
Plate and Heavy shields
Twofold Pact: Fey Pact:
This comes with the Boon; now you teleport when your curse target drops
Human Power Selection: Bonus At-Will Power
Background: Born Under a Bad Sign (Born Under a Bad Sign Benefit):
Can change this but it fits a Paladin/warlock to the tee if you ask mee; extra HPs yay!
FINAL ABILITY SCORES
Str 11, Con 16, Dex 14, Int 16, Wis 9, Cha 21.
(You can pump INT only but a Healing Surge and +1 in FORT is okay ... level 14 seems so far away to me, which is where you'd finally get your 18 INT)
STARTING ABILITY SCORES
Str 10, Con 14, Dex 13, Int 14, Wis 8, Cha 16.
AC: 27 Fort: 22 Reflex: 22 Will: 23
HP: 84 Surges: 11 Surge Value: 21
TRAINED SKILLS
Arcana +13, Religion +13, Bluff +15, Intimidate +15, Stealth +12
UNTRAINED SKILLS
Acrobatics +7, Diplomacy +10, Dungeoneering +4, Endurance +8, Heal +4, History +8, Insight +4, Nature +4, Perception +4, Streetwise +10, Thievery +7, Athletics +5
FEATS
Human: Heavy Blade Expertise: Pretty unavoidable
Level 1: Hybrid Talent:
This is where you get your Heavy Armour
Level 2: Weapon Proficiency (Fullblade):
Bastard Sword is okay if you want to get a Heavy Shield instead but when your crit range increases to 18-20 at level 11 ... devastating!
Level 4: Shadow Initiate:
The path to gain Shadow Walk; You can now use your sword as your implement! oh and stealth boost ... plus Shrouds. Good deal!
Level 6: White Lotus Riposte:
Of course
Level 8: Cursed Shadow:
Hello Shadow Step!
Level 10: Crimson Fire:
Marked and Cursed targets = curse damage uses d10s!
I prefer this over turning your Paladin At Will to a Arcane Power (Domain of Arcana?), but it's an option. Alternatively, Dragonmark of Warding is another sound option. You'll get both those feats anyway at some stage.
Level 11: Twofold Pact:
Second Pact, this time with Boon! And Eyebite! SO retrain Eyebite for Hand of Blight or Enfeebling Strike
POWERS
Bonus At-Will Power:
Eyebite: Mark, and Blind at Range ... PITA!
Hybrid at-will 1: Eldritch Strike:
Bread and Butter
Hybrid at-will 1: Virtuous Strike:
Cha MBA; Pretty Crappy but it does deal Radiant Damage so okay vs Undead at least ... gets decent if you gain Domain of Arcana and possibly convince your DM to allow Corellon to gain access to the Domain of the Sun
Hybrid encounter 1: Valorous Smite:
Mark everything within 3 of you with your Sanction
Hybrid daily 1: Crown of Stars:
Warlock Radiant Power that gives you an encounter long minor action Warlock Radiant Power Attack; see Student of Caiphon + Full Blade which is your Implement
Hybrid utility 2: Bless Weapon:
Doesn't say it works only on melee attacks ... so all your Implement attacks through your Blessed sword gain this AWESOME benefit for 1 encounter per day
Hybrid encounter 3: Otherwind Stride:
Get in and get out!
Hybrid daily 5: Hallowed Circle:
That's quite a big explosion ... lots of attacks, lots of chances to crit! High Crit Weapon! And while your sword is Blessed ...awesome
Hybrid utility 6: Shadowslip:
Move towards or away from offending enemy that attacks you from afar
Hybrid encounter 7: Far Realm Phantasm:
If you hit, the next turn the enemy attacks thin air! Pretty awesome vs a solo creature or an elite Boss creature.
Hybrid daily 9: Radiant Pulse:
Again ... sustaining encounter long lots of Radiant Warlock Power attacks; see Student of Caiphon etc.
Hybrid utility 10: Font of Healing:
Heal yourself and a friend; warlocks need something to get other people to like them, right?
ITEMS:
I don't put much thought into items; DM territory afaic.
Fullblade of Great Opportunity +2, Teleporting Wyvernscale Armor +3, Cloak of the Walking Wounded +2