Well, the flipside works a fair bit better. Warlock with Wiz MC.
Tiefling ('cos they rock)
Either star pact or infernal pact, with this statline:
Str 10
Con 16
Dex 13
Int 18
Wis 8
Cha 13
K, I like that statline, but apart from the 16s in con and int, it's flexible.
Take hellfire blood, to make up for a con deficiency with fire & fear powers.
Sure, at that point your eldritch blast would be weak, but I'd happily trade -1 average damage for the other at will's +1 to hit and extra effect.
Pick up scorching burst as your wiz multi .. that one gets +5 to hit and damage ..

As well, if you went with infernal pact, you can catch
yourself in your scorching burst the turn after landing a hellish rebuke ... with your fire resist, it's minimal pain for extra damage.
Even if you went star pact, and your pact's power choice(s) aren't based on con, grab the infernal pact option.
Maybe do the encounter power swap at 4 to take fire shroud to capitalise on your higher int.
Just a few ideas.