I'm not sure about the deviated Titans bit, as Rassimov indicated that they were completely different. However, both seem to have originated from Huntik, so I wouldn't expect them to be all that different. What seems to be indicated, though indirectly, is that the Nullifiers were / are naturally evil as their sole purpose appears to be the destruction of planet Earth.

My personal take would be that they're something of the antithesis to the Titans. The Titans are generally neutral (think balance / order) while the Nullifiers are generally destructive (think chaos / disorder). Though the Titans are still influencable to some extent.  Bonding with a really good or evil Seeker for a long period will affect the Titan's behavior and ability to bond. For Nullifiers, not much is really stated about bonding or even if a bond is required to invoke one.

You see, i have a competely different answer which varies almost totally from the season finale.I belife the nullifiers did indeed originate from huntik, but the cannot directly find earth. I belive the inhabit one sinlge planet now,and as we see, the spiral mark lights the earth up in space wtih a red light. and as we know, void was a scout and just a scout. And alot of stuff seems to have to do with space. so therefore, the nullifiers are simply  very evil, nearly impossible to control, idependantly thinking titan-ish of nature alien.

4-going on 5 years later and what's dissapointing is that these big bads would've introduced Lovecraftian creatures of every shape and size as antagonists if there had been a season 3. Thanks 4Kids for losing the battle. Now we'll never know.

I agree, there was so much potential for Season 3 to find a bigger and darker stance than before and I love the idea of Lovecraft's creations coming into the show.