The main reason handlock loses to hunter is because it is very slow to establish board since they aim for big azuredrake value or giants on turn 4. And then they have hunter's mark and deadly shot to deal with the giants once they finally arrive. But, spectral knight reduces the concern to only deadly shot and hunters may only run one of those if any and still has to often luck out on the RNG.
If I used warlock I think I'd still run 2 molten giants, but not 2 mountain giants. I think it would look more like a demonlock deck than handlock.
edit:
This is what I am trying out so far. 3-0 so far:
http://s29.postimg.org/50w70e953/modded_cotv.png
I haven't actually played a spectral knight yet tho lol, but I guess that is a good thing since I was ahead each match and didn't need to make a difficult to remove taunt minion. So cool getting a free doomguard... and then faceless on it! And it hasn't happened yet, but I could get a free doomguard, poweroverwhelming 2x, then faceless it... 23 damage as early as turn 7. Add in a soulfire or two and its potentially a 30-0 situation.